Filter cartridges; features and methods of assembly; air cleaner assemblies; and, filter cartridge combinations

ABSTRACT

Filter cartridge arrangements, features thereof and assembly for use therewith, are provided. Selected filter cartridge features are disclosed. Methods of assembly and systems for use are described.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Ser. No. 15/935,271, filedMar. 26, 2018. U.S. Ser. No. 15/935,271 is a continuation of U.S. Ser.No. 14/646,532, filed May 21, 2015, now U.S. Pat. No. 9,925,485. U.S.Ser. No. 14/646,532 is a National Stage of International Application No.PCT/US2013/072495, filed Nov. 29, 2013, which claims benefit of U.S.Ser. No. 61/731,259, filed Nov. 29, 2012; U.S. Ser. No. 13/834,885,filed Mar. 15, 2013, now abandoned; and, U.S. Ser. No. 13/841,440, filedMar. 15, 2013, now U.S. Pat. No. 9,067,161. The above referencedapplication includes with edits, the disclosures of U.S. Ser. No.13/841,440, filed Mar. 13, 2013; and, U.S. Ser. No. 13/834,885, alsofiled Mar. 15, 2013, each of which included the disclosure of, withedits, U.S. Ser. No. 61/731,259, filed Nov. 29, 2012. The completedisclosures of U.S. Ser. Nos. 15/935,271; 14/646,532; PCT/US2013/072495;U.S. Ser. No. 13/841,440; U.S. Ser. No. 13/834,885; and, U.S. Ser. No.61/731,259 are incorporated herein by reference. To the extentappropriate, a claim of priority is made to U.S. Ser. Nos. 15/935,271;14/646,532; PCT/US2013/072495; U.S. Ser. No. 13/841,440; U.S. Ser. No.13/834,885; and, U.S. Ser. No. 61/731,259.

FIELD OF THE DISCLOSURE

The present disclosure relates to filter assemblies, filter cartridges,features and techniques. Certain selected example features andtechniques described are configured to be particularly convenient as, orfor use with, secondary or safety filter cartridges for air or other gasfilter arrangements and assemblies. Also, advantageous main filtercartridges and advantageous filter assemblies are also described.Preferred features of selected filter cartridges, filter assemblies, andmethods of assembly are described.

BACKGROUND

Gas filters are used in a variety of assemblies and systems. Forexample, it is desirable to filter intake air to a variety of vehiclesand other equipment. Typically, the intake air is combustion air for aninternal combustion engine, often a diesel engine. Filtration isgenerally conducted with a gas (air) cleaner assembly (i.e. a filterassembly) typically including a housing and an internally positionedfilter cartridge arrangement. The filter cartridge arrangement typicallyincludes a main filter cartridge, through which the air is passed andwhich is operated with deposition of particulate material carriedtherein onto filter media of a main filter cartridge. In a variety ofair cleaner assemblies, the main filter cartridge and the remainder ofthe assembly are configured for out-to-in flow during filtering, inreference to direction of air flow through the media of the main filtercartridge, during normal operation. When this is the case, the media ofthe main filter cartridge is typically configured surrounding an openfilter interior that is a clean air side of the media.

In many instances, a safety or secondary filter cartridge is includedwithin the filter assembly. When a safety or secondary filter cartridgeis used with an assembly configured for out-to-in flow during filtering,the safety filter is typically configured with media thereof surroundingan open filter interior and projecting into an open filter (clean gas)interior of the main filter cartridge. Thus, after the gases (air) passthrough the media of the main filter cartridge, the gases (air) passthrough the media of the safety filter cartridge as those gases (air)are directed toward an outlet from the air cleaner.

In a typical assembly, both the main filter cartridge and the safetyfilter cartridge are configured as service components. That is, they areconfigured to be removable from, and to be replaceable within, the aircleaner assembly. As a result, each is typically provided with areleasable housing seal, i.e., a seal which removably seals to a portionof the housing or air cleaner assembly, when the two filter cartridgesare properly and operably positioned. Such seals are sometimes referredto as “releasable seals” since they can be established and be removedwithout damage to the cartridges or housing component(s) engaged.

A variety of assemblies have been developed which can use such generalarrangements. Examples are described in WO 2009/014986 A1 and WO2012/116314 A1, each which is incorporated herein by reference and whichare owned by the owner of the present disclosure, Donaldson Co., Inc.,of Bloomington Minn.

Issues relating to the safety or secondary filter cartridgeconfiguration concern limitations in its size and shape imposed by therequirements of the gas filter assembly for location of the safetyfilter, typically enclosed within the main filter cartridge yet stillmeant to be removably sealed to a feature of the air cleaner assembly orhousing; and the preferred desire to be able to service the main filterwithout dislodging the safety. Improvements have been sought.

In addition, main filter cartridge features are generally sought to beimproved, with respect to a variety of such issues as: managingappropriate interaction with a safety filter cartridge or othercartridge support when present; and, for appropriate housing interactionas well as secure installation and convenient assembly. Featurescharacterized herein facilitate this in selected applications.

Herein, in addition, selected features and filter assemblies, includinghousings therefor, for advantageous use, assembly, and operation aredescribed. Also, methods are depicted.

SUMMARY

According to the present disclosure, some advantageous features offilter assemblies, such as air cleaner assemblies are provided. Selectedadvantageous features concern a variety of components for such anassembly. Selected features described and disclosed relate to one ormore of: a main filter cartridge; a housing; and, a secondary or safetyfilter cartridge. There is no specific requirement that all of theadvantageous features with respect to all of the components described beimplemented, in order to obtain some advantage according to the presentdisclosure.

According to one aspect of the present disclosure, a filter cartridge,typically to be used as a secondary or safety filter cartridge by beingpositioned with media thereof oriented projecting into an open interiorof a main filter cartridge, is provided. The safety or secondary filtercartridge comprises an extension of media, typically surrounding an openfilter interior and having a first end and the second end. In preferredconfigurations, at the first end, the media either: has no pleats; or,if pleated, preferably has no pleats greater than about 3 millimeters indepth, more preferably no greater than 2 mm in depth. However, at thesecond end, in most preferred applications, the media is pleated, with apleat depth of at least 5 mm, typically at least 10 mm and often atleast 15 mm.

This overall media and pleat configuration can be provided in a filtercartridge with a variety of additional features, to substantialadvantage, as discussed below. In addition, it allows for anadvantageous combination with main filter cartridge features and/orfilter assembly features generally.

According to an alternate aspect of the present disclosure, somefeatures and techniques usable in a media support, for advantageouslysecuring a filter cartridge in place, especially a secondary safetyfilter cartridge, are discussed and described. These can be used incombination with the preferred pleat feature(s) identified above, or inalternate configurations as desired. In an example depicted, an end of aframe for the cartridge includes an aperture therethrough, which islined, and in some instances closed, by a cushion and/or seal (grommet)member. The housing can include structure that projects into engagementwith the cushion and/or seal member, to advantage. Also, a maincartridge can include features that engage the cushion and/or sealmember, to advantage.

Also, herein selected advantageous structural features, for examplemedia support features, for preferred filter cartridges are described.These can be used in association with the various features describedpreviously in this section, or independently, to advantage.

Methods of assembling a filter cartridge in accord with the featuresdescribed herein are also provided. The methods can be used toadvantage, to achieve a desirable filter cartridge in an efficientmanner.

Also according to the present disclosure, filter assemblies, includingfeatures specifically and advantageously configured for use withpreferred filter cartridges are described herein are shown anddescribed. Also main or primary filter cartridge configurations thatparticularly well adapted for use with components as characterizedherein are described. Further, methods of installing main filtercartridges are described

There is no specific requirement that a filter cartridge or componentinclude all of the features specifically characterized herein, or evenas specifically characterized above in this section, in order to obtainsome benefit according to the present disclosure. Further, there is nospecific requirement that the features described herein, in the contextof a safety or secondary filter cartridge, only be implemented in asafety filter cartridge, as opposed to an alternate filter cartridge,unless otherwise specifically recited. In addition, while the techniquesare described in connection with air filtration, they can be appliedwith other types of gas filters or in filtering of other media. It isnoted, however, that the techniques were particularly developed for, andare particularly advantageous for, air filter applications, especiallythese involving either or both of: a secondary or safety filtercartridge; and, a central support position in the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The general features of FIGS. 1-15 were included in the identifiedpriority document U.S. Ser. No. 13/841,440, filed Mar. 15, 2013 andincorporated herein by reference.

FIG. 1 is a schematic cross-sectional view of a filter cartridgeaccording to the present disclosure; the view being taken generallyalong line 1-1, FIG. 2.

FIG. 1A is an enlarged, fragmentary, schematic view of a firstidentified portion of FIG. 1.

FIG. 1B is an enlarged, fragmentary, schematic view of a secondidentified portion of FIG. 1.

FIG. 1C is a schematic cross-sectional view analogous to FIG. 1, showingsome optional variations in the filter cartridge of FIG. 1D.

FIG. 1D is an enlarged fragmentary schematic view of an identifiedportion of FIG. 1C.

FIG. 1E is an enlarged fragmentary schematic view of an identifiedportion of FIG. 1C.

FIG. 2 is a schematic enlarged end view of the filter cartridge of FIG.1; the view being taken toward a top end in the view/orientation of FIG.1.

FIG. 2A is a view analogous to FIG. 2, but of the cartridge as depictedin FIG. 1C.

FIG. 3 is a schematic, enlarged, second end view of the filter cartridgeof FIG. 1; the view of FIG. 3 being taken toward the bottom end of theview/orientation of FIG. 1.

FIG. 4 is a schematic exploded view of the filter cartridge of FIG. 1.

FIG. 5 is a schematic perspective view of a frame piece component of thecartridge of FIG. 1.

FIG. 6 is a schematic end view of the frame piece of FIG. 5; the view ofFIG. 6 being taken toward the top end of the view/orientation of FIG. 5.

FIG. 7 is a schematic cross-sectional view of the frame piece of FIG. 5,taken generally along line 7-7, of FIG. 6.

FIG. 8 is a schematic perspective view of a filter media component ofthe filter cartridge of FIG. 1.

FIG. 9 is a schematic end view of the filter media component of FIG. 8;the view of FIG. 9 being taken toward the top end of theview/orientation of FIG. 8.

FIG. 9A is a view generally analogous to FIG. 9, with selecteddimensions indicated.

FIG. 10 is a schematic side elevational view of the media component ofFIG. 8.

FIG. 11 is a schematic cross-sectional view of an example housing foruse in an air cleaner assembly that can include a cartridge according toFIGS. 1-10, according to the present disclosure.

FIG. 11A is a schematic enlarged fragmentary view of a selected portionof FIG. 11.

FIG. 11B is an enlarged fragmentary schematic view of a second selectedportion of FIG. 11.

FIG. 12 is a schematic cross-sectional view of a housing of a filterassembly according to the present disclosure, having a safety cartridgein general accord with FIGS. 1-10 installed therein.

FIG. 12A is an enlarged fragmentary schematic view of a selected portionof FIG. 12.

FIG. 12B is an enlarged fragmentary schematic view of a selected portionof FIG. 12.

FIG. 12C is a schematic view generally analogous to FIG. 12, withselected dimensions indicated.

FIG. 13 is a schematic cross-sectional view of an air cleaner assemblyaccording to the present disclosure having a main filter cartridgetherein and a safety filter cartridge in accord with FIGS. 1-10installed therein.

FIG. 13A is an enlarged schematic fragmentary view of an identifiedportion of FIG. 13

FIG. 13B is an enlarged fragmentary schematic view of a secondidentified portion of FIG. 13.

FIG. 14 is a schematic cross-sectional view of an alternate housing tothe housing depicted in FIG. 11, usable in accord with the principles ofthe present disclosure.

FIG. 15 is a schematic cross-sectional view of an alternate main filtercartridge, to the cartridge depicted in FIG. 13 and usable inarrangements according to the present disclosure.

The following FIGS. 16-57, were not included in the various prioritydocuments identified above and incorporated herein by reference.

FIG. 16 is an exploded, schematic, perspective view of an air cleanerassembly including selected components according to selected features ofthe present disclosure.

FIG. 17 is a schematic side elevational view of the air cleaner assemblyof FIG. 16.

FIG. 18 is a schematic end plan view of the air cleaner assembly of FIG.17.

FIG. 19 is a schematic bottom plan view of the air cleaner assembly ofFIG. 17.

FIG. 20 is a schematic outlet end view of the air cleaner assembly ofFIG. 17.

FIG. 21 is a schematic perspective view of a main filter cartridgecomponent of FIG. 16-20.

FIG. 22 is a schematic open end plan view of the filter cartridge ofFIG. 21.

FIG. 23 is a schematic side elevational view of the filter cartridge ofFIG. 21, with portions shown broken away and in cross-section.

FIG. 24 is a schematic cross-sectional view of the filter cartridge ofFIG. 21.

FIG. 25 is a schematic exploded perspective view of a filter cartridgeof FIG. 21.

FIG. 26 is a schematic cross-sectional view of an inner liner componentof the filter cartridge of FIG. 21.

FIG. 27 is an open end plan view of the liner component of FIG. 26.

FIG. 28 is a schematic closed end plan view of the liner component ofFIG. 26.

FIG. 29 is a schematic perspective view of the liner component of FIG.26.

FIG. 30 is an enlarged fragmentary schematic cross-sectional view of theliner component of FIG. 29, taken adjacent the closed end thereof.

FIG. 31 is a schematic exploded perspective view of the housing bodycomponent of the air cleaner assembly of FIGS. 16-20.

FIG. 32 is a schematic perspective view of a center support member ofthe housing body of FIG. 31.

FIG. 33 is a schematic cross-sectional view of the support component ofFIG. 32.

FIG. 34 is a schematic enlarged fragmentary view of an identifiedportion of FIG. 33.

FIG. 35 is a schematic closed end perspective view of the supportcomponent of FIG. 32.

FIG. 36 is a schematic open end perspective view of the supportcomponent of FIG. 33.

FIG. 37 is an exploded perspective view of a secondary or safety filtercomponent of the air cleaner assembly of FIGS. 16-20.

FIG. 38 is a side elevational view of the filter cartridge component ofFIG. 37, with a portion shown broken away in cross-section.

FIG. 39 is a closed end plan view of the secondary or safety filtercartridge component of FIGS. 37 and 38.

FIG. 40 is an enlarged fragmentary schematic cross-sectional view of anidentified portion of FIG. 38.

FIG. 41 is an enlarged perspective view of a grommet or resilientcushion component of the cartridge of FIGS. 37 and 38.

FIG. 42 is a schematic cross-sectional view of the component of FIG. 41.

FIG. 43 is a schematic open end plan view of the component of FIG. 42.

FIG. 44 is a schematic side elevational view of the secondary or safetyfilter cartridge component of FIG. 37.

FIG. 45 is a schematic closed end partially cross-sectional view of thecartridge of FIG. 44 with portions broken away.

FIG. 45A is an enlarged fragmentary schematic cross-sectional view of anidentified portion of FIG. 45.

FIG. 46 is an enlarged fragmentary schematic cross-sectional view of aselected portion of an air cleaner assembly in accord with FIGS. 16-20.

FIG. 47 is an enlarged fragmentary schematic cross-sectional view of aportion of an air cleaner assembly in accord with FIGS. 16-20.

FIG. 48 is a schematic side elevational view of an additional aircleaner assembly according to the present disclosure.

FIG. 49 is a schematic exploded perspective view of the air cleanerassembly of FIG. 48.

FIG. 50 is a schematic cross-sectional view of the air cleaner assemblyof FIG. 48.

FIG. 51 is an enlarged fragmentary schematic cross-sectional view of anidentified portion of FIG. 50.

FIG. 52 is an enlarged fragmentary schematic cross-sectional view of anidentified portion of FIG. 50.

FIG. 53 is a schematic side elevational view of an additional aircleaner assembly according to the present disclosure.

FIG. 54 is a schematic exploded perspective view of the air cleanerassembly of FIG. 53.

FIG. 55 is a schematic cross-sectional view of the air cleaner assemblyof FIGS. 53 and 54.

FIG. 56 is an enlarged fragmentary schematic cross-sectional view of aportion of FIG. 55.

FIG. 57 is an enlarged fragmentary schematic cross-sectional view of aportion of FIG. 55.

DETAILED DESCRIPTION I. An Improved Secondary or Safety Filter CartridgeGenerally, FIGS. 1-10 A. Further Regarding Safety or Secondary Cartridgeuse in Filter Assemblies Generally; Some Selected Issues of Concern

As indicated previously, in general portions of the present disclosurerelate to features and techniques that are specifically adapted foradvantageous use in secondary or safety filter cartridge arrangementsand assemblies; although the techniques can be applied in otherapplications. The techniques are understandable, for example, in thecontext of use in an air cleaner assembly, such as ones having featuresas generally described in WO 2009/014986A1 or WO 2012/116314 A1,incorporated herein by reference.

In general, such filter assemblies comprise an air cleaner housing and aprimary or main filter cartridge. The main filter cartridge typicallycomprises media surrounding an open filter interior. The assembly istypically configured for “out-to-in” flow during filtering, with respectto gas (air) flow direction through the media of the main filtercartridge. By the term “out-to-in” flow in this context, it is meantthat the flow during filtering through the media of the main filtercartridge is generally: from a region outside of the cartridge, throughthe main cartridge media, to the open filter interior of the maincartridge surrounded by media. Thus, the open filter interior of themain filter cartridge is a clean air region.

The main filter cartridge is positioned to be loaded with contaminantthereon during use, and is, as a result, typically constructed as aserviceable component. Thus, the housing is typically configured with amain housing body or base section and an access cover; the access covercomprising a serviceable cover removable for internal servicing. Themain filter cartridge is typically configured to be removably installedwithin the housing interior. To accomplish this, the main filtercartridge has a releasable housing seal. By “releasable”, in thiscontext, it is meant that the seal is established by the main cartridgeengaging a selected portion of the housing (or assembly) when thecartridge is installed, and the seal is readily removed and releasedwhen the cartridge is removed from the housing. Such “releasable” sealsare capable of being separated or removed without damage to either themain filter cartridge or the housing.

Many features concerning main filter cartridge configuration, relate to:ensuring a desirable amount of filter media surface area available forload, given limitations on volume, etc.; ensuring that the housing sealis configured so that the seal is properly established and maintained;and, ensuring that the cartridge cannot be misinstalled and/or that analternate, inappropriate, cartridge cannot be inadvertently installed inthe system. A variety of constructions have been developed to addressthese issues, including the general ones described in WO 2009/014986 A1and/or WO 2012/116314 A1.

A housing, for example of an air cleaner assembly, is typically providedwith an outlet air (gas) conduit or tube, in communication with openinterior of the main filter cartridge. Thus, the housing seal on themain filter cartridge is typically either sealed to the outlet flowtube, or to a portion of the housing that surrounds a volume with whichthe outlet flow conduit or tube communicates. Herein, the portion of theair cleaner assembly to which the seal of the main cartridge releaseablyengages, will be referred to as a portion of the housing, whether it isan outlet separable from a remainder of the housing structure, or somestructure integral with other portions of the housing structure.

In many systems, it is desirable to provide the air cleaner assemblywith a serviceable safety or secondary filter cartridge. The safety orsecondary cartridge is typically positioned in the air (gas) flow pathbetween the main filter cartridge, and the outlet flow exit of filteredair (gas) from the filter assembly (housing). When the main filtercartridge is configured for “out-to-in flow” during filtering, thismeans that the safety or secondary cartridge is typically positionedwith at least a portion thereof oriented within the main filtercartridge interior.

Herein, the terms “secondary” or “safety” when used in reference to afilter cartridge positioned with media downstream of the main filtercartridge, are meant to be used interchangeably and withoutdifferentiated meaning.

Preferably, the safety filter cartridge is an optional serviceablecomponent independent of the main filter cartridge. This means: that themain filter cartridge can be installed in, and be removed from, thehousing, without removing (and preferably without dislodging from propermounting) the optional safety cartridge; and, that servicing the mainfilter cartridge does not necessarily require servicing the optionalsafety filter cartridge.

Independent main and safety cartridges are advantageous for a number ofreasons. An advantage, is that when the main cartridge is serviced, thesafety cartridge can be left in place so as to avoid dirt and dust fromentering the clean gas (air) plenum of the gas (air) cleaner system, forexample as an interior of the housing is cleaned. Other advantagesrelate to convenience of installation and assembly, as well asconvenience of component manufacture. In addition, separate constructionallows for efficient material usage and disposition, especially sincethe main filter cartridge may need to be serviced, or be removed forinspection, more often than the safety cartridge.

There are a number of issues relating to safety or secondary filtercartridge configuration and assembly. For example, in many air cleanerassemblies, there is little option available for location of sealingbetween the housing and the safety filter cartridge. One regionsometimes available, is an interior (or exterior) of a flange or tubularsurface that surrounds a gas exit flow from the housing. This could, forexample, comprise a surface of an outlet flow tube, or it could comprisea surface of a flange that projects into the housing at a locationsurrounding, but spaced from, the outlet flow tube.

When a cartridge seals to such a flange or tube, the seal is sometimesreferenced as “radially” directed. By this, it is meant that the sealforces are generally directed around a central axis, with the forces ofsealing being generally directed toward or away from that central axis.Typically, the central axis referenced, is an axis through an air flowexit from the associated cartridge, typically an axis also surrounded bythe media. A seal may be referred to as “radially outwardly directed”and by similar terms, if the seal engages a housing component thatsurrounds the seal during use; and, the seal may be generallycharacterized as “radially inwardly directed” or by similar terms, whenthe seal is configured to surround and engage the housing component inuse.

An issue with radially directed seals, is that they can take-up radialdimension within the housing. This reduces the cross-sectional areaavailable for gas flow exiting the cartridge and/or housing, and canundesirably add to restriction.

Of course, the housing in which the safety cartridge is used can be madesufficiently large to minimize this problem, but there are limitationsimposed on this by: a preference for the main filter cartridge to haveas much surface area and media volume as reasonably possible; apreference that the air cleaner be as small and light as reasonablypossible; cost and material issues; and, issues with handling andshipping components.

The restriction issue presented by reduction in cross-sectional areadefined by the safety cartridge for air flow, as characterized in thissection, relates to the dimension of radial direction (width) of thesecondary or safety filter cartridge toward a central axis, from theseal surface, i.e. the part of the radial seal positioned to sealinglyengage the housing. In general, it is desired that this amount of radialwidth or extension of the safety cartridge structure be maintained assmall as reasonably possible, so as to ensure that the outlet flowcross-sectional size, through an end of the safety filter cartridge andto the outlet from the housing, remains as large as reasonably possible.

A variety of techniques have been implemented to manage this issue withthe safety cartridge. An example depicted in WO 2012/116314, includesconfiguring the safety cartridge from non-pleated media, so as to limitthe amount of radial dimension taken up by the media. Such techniqueshave been applied in a wide variety of safety filter or secondary filterelement configurations.

However, there are issues presented from using non-pleated media. Inparticular, it limits the amount of media surface area in a safetyfilter available for filtering. In general terms, the surface area ofmedia available in the filter cartridge is preferably as large asreasonable for the volume available. This renders advantageous mediaface velocities. Media face velocity is generally the gas flow ratethrough the media divided by upstream surface area of the media. Smallermedia surfaces lead to higher face velocities. Higher face velocitiesare typically less desirable than lower face velocities for a number ofreasons. For example, higher face velocities generally result in agreater restriction placed on air flow through the air cleaner assembly,which is undesirable with respect to equipment operation and filterlifetime. Also, the higher the face velocity, the more likely a particlecan penetrate through the media and reach the clean air (gas) plenum.

It can be understood that non-pleated media of a given outer perimetersize has a higher face velocity than pleated media which defines thesame outer perimeter size (i.e., outer perimeter size disregarding pleatpresence). However, introduction of pleats into the media has generallybeen undesired for certain secondary filters, as pleats introduce radialwidth dimension to the cartridge, which leads to increase in restrictionto gas flow outwardly from the cartridge and assembly. Herein in thenext section, selected filter cartridge features are described, whichcan be applied to balance these issues to advantage.

In addition, especially with a safety cartridge that projects into theopen interior of the main cartridge during use, gas flow exiting themain cartridge and being directed toward the gas flow outlet can beaffected by the shape features of the secondary cartridge. Advantageousshape features are discussed in the next section, which can lead to moredesirable flow characteristics. This can help limit restriction increaseand provide more desired filter assembly operation.

The issues of limited surface area available for secondary or safetyfilter systems are exacerbated, when the main filter cartridge tapersdownwardly in extension from an exit end toward a remote end of thecartridge. This is because the inward tapering of the main filtercartridge reduces cross-sectional area into which the safety filter canproject, adjacent an end of the main filter cartridge remote from theair flow exit. Techniques described herein can be applied advantageouslyto manage such issues, in a variety of systems.

B. An Example Filter Media Configuration FIGS. 1-10.

The reference numeral 1, FIG. 1, generally depicts an example filtercartridge in accord with selected, optional, improvement according tothe present disclosure. The example filter cartridge 1 depicted, isconfigured with features advantageous for use in a safety or secondaryfilter cartridge, for example to be used in an assembly configured forout-to-in flow through a main filter cartridge during operation; and, inwhich the secondary filter cartridge is configured to be sealed radiallyto a surface of a housing component tube or (flange), with a media ofthe safety filter cartridge projecting into an open filter interior of amain cartridge. It will be understood that the selected advantageousfeatures described herein, however, can be applied in a variety ofalternate applications/configurations.

Referring to FIG. 1, the filter cartridge 1 depicted comprises anextension 2 e of media 2 extending between first and second media ends3, 4. In general terms, the media 2 surrounds a central axis X anddefines an open interior 2 i, which corresponds to a clean gas (air)side of the media 2.

The first media end 3 is positioned at an exit end for filter and gases,from the filter cartridge 1. That is, end 3 of the media corresponds toan open exit flow end 7 of the filter cartridge 1, for filtered gasesflow during use. It is in regions adjacent end 7 that it is mostdesirable that the filter cartridge 1 maintain a relatively small radial(width) dimension, so as to avoid increasing restriction to gas flowexit, to an extent reasonable.

To provide for the advantageous opening 7, preferably media 2, at end 3,is non-pleated or minimally pleated. By “minimally pleated” in itscontext, it is meant that if there is any pleat definition at end 3 atall, it is no more than 3 mm in pleat depth. Preferably, any such pleatdefinition is with a pleat depth of no more than 2 mm and morepreferably no more than 1 mm. By “pleat depth” in its context, referenceis meant to a dimension of a pleat radially inwardly from an outermostperimeter, in a direction toward central axis X. Most preferably at end3, the media 2 is not pleated at all, i.e. it has no pleat depth.

However, as explained above, it is desirable to provide the media 2 witha surface velocity as low as reasonable. Thus, it is desired for themedia 2 to have a pleated configuration in spite of the fact that it isdesirable to have minimal or no pleat depth at end 3. To accommodatethis, the media 2 is provided with a pleat definition adjacent secondend 4. Preferably the pleat definition is one that decreases in pleatdepth in a direction of pleat extension from end 4 toward end 3. Such apleat is shown in FIG. 1, for example, at 10, with a pleat depth at end4 being at least 5 mm, preferably at least 10 mm, often at least 15 mm,and in many instances 20 mm or more. Indeed, for a typical application,a pleat depth at end 4, (i.e. at the second end of the media), on theorder of 15-40 mm is typical, although alternatives are possible. Thiscan be used to provide a media area at least 10%, typically at least20%, and often 25% or more, greater than a media area if non-pleatedmedia of the some outer perimeter size, is used.

In general terms, adjacent the second end 4, the media 2 is pleated,comprising a plurality of pleats having a pleat depth of at least 5 mmand preferably as defined. Herein, when it is said that a “plurality ofpleats” has this definition, it is not meant that every pleat adjacentthe end 4 must have this definition, but merely that there be a set orplurality of them of that does. In a typical example as depicted,however, every pleat adjacent end 4 has a pleat depth in accord with thecharacterizations of the previous paragraph, to achieve preferable mediaarea increase.

An example media configuration depicted to provide for this definition,can be understood by reference to FIG. 8. Referring to FIG. 8, the media2 is depicted surrounding axis X and in extension between first, in theexample non-pleated (or minimally pleated) end 3, and, opposite, second,end 4. The second end 4 comprises a plurality of inwardly directed(inner) pleats 10 and a plurality of outwardly directed (outer) pleats11; the inner pleats 10 and outer pleats 11, alternating. In a typicalapplication of the principles according to the present disclosure, media2 will comprise at least 5 each of inner pleats 10 and at least 5 suchouter pleats 11, and typically not more than about 15 of each. A typicalnumber will be within the range of about 6-12 inclusive, althoughalternatives are possible.

The techniques described herein can be applied with an alternate numberof pleats, and the number of pleats is not critical to obtain someadvantage. However, relatively few pleats (12 or less) that haverelatively wide pleat definitions facing radially outwardly, i.e. alongthe outer perimeter, can be advantageous for desirable gas flowcharacteristics and avoidance of undesirable gas flow restriction.

Referring to FIGS. 9 and 9A, views taken toward media end 4, typicallythe outer pleats 11 will have a generally wide, rounded, as opposed tosharp, pleat tip definition, for example, defining a radius at end 4 foreach pleat 11 of at least 3 mm, typically at least 4 mm, for exampletypically 4-11 mm, inclusive. This will be advantageous with respect toformation of the configuration, although alternatives are possible. Theinner pleats 10, however, will typically be formed more sharp and to asmaller radius of curvature. A typical radius for the inner pleat tipswould be no larger than 3 mm and often no larger than 2 mm.

As indicated, the outer pleats 11 are typically and preferablyrelatively wide. By this, it is meant that the opposite sides 11 a, 11b, FIG. 9, of the pleats 11, adjacent end 4, generally diverge from oneanother at an angle of at least 10°, typically at least 15°, for examplein the order of 15-30°, inclusive; and/or the pleat sides 11 a, 11 breach a distance apart from one another of at least 8 mm, usually atleast 10 mm and often 10-20 mm, within a selected distance from theoutermost pleat tip 11 t of no greater than about 15 mm.

The relatively wide, rounded, outer tips 11 t of the outer pleats 11provide for a large outside surface area for engagement with supportstructure, as discussed below. It is desirable to avoid a sharp point atpleat tips 11 t, at least for that reason. The relatively sharp internalpleats 10 t provide for convenient assembly and manufacturing, as wellas desirable media characteristics and flow characteristics.

Referring to FIG. 9, it is noted that the outer pleat tips 11 t,adjacent end 4, are angularly spaced rather widely, with spacing (oncenter) being on the order of at least 30°, typically 30-50°, inclusive,(usually 35°-50°, inclusive) around central axis X. The dimension ofthis spacing (outer pleat tip 11 t to outer pleat tip 11 t) is typicallyat least 20 mm, usually at least 30 mm, for example 35 mm to 55 mm,inclusive. Also, the inner pleat tips, adjacent end 4, are spaced ratherwidely, typically at least 30° often at least 35° and usually in theorder of 35°-50°, inclusive. This creates long, wide flow channels onthe exterior 11 c and on the interior 10 c, along which gases can flowtoward the outlet end 3. This provides an arrangement that is desirablewith respect to management of gas flow restriction issues, and is areason why it is desired to not have an excessive number of pleats(greater than 12, and typically 10 or less) in spite of the advantagesfrom increased surface area and lower face velocity.

In FIG. 9A, some example dimensions are provided as follows: ZX=1.5 mmradius; ZY=8 mm radius; ZW=124.7 mm diameter; ZC=2 mm; YA=119 mm; and,YB=124.7 mm.

In FIG. 10, example dimensions are as follows: AE=379 mm; AF=124.7 mm.

C. Media Support and Filter Cartridge Features; FIGS. 1-7

Typically, the outermost tips 11 t of outer pleats 11 and innermost tips10 t of a plurality of the pleats 10 will extend generally straight, inextension from end 4 in a direction toward end 3. Typically, the outerpleat tips 11 t will either extend parallel to central axis X, or at anacute angle of no less than 88° and typically no less than 89° withrespect to a plane perpendicular to central axis X. Typically, the pleattips 11 t of a plurality of pleats 11 extend at an angle relative to aplane perpendicular central axis X of about 88-90°, inclusive.

A plurality of inner pleat tips 10 t, typically extend radiallyoutwardly from central axis X substantially, and extend at an acuteangle of no greater than 88°, typically no greater than 87° and oftenwithin the range of 75°-86°, inclusive, relative to a planeperpendicular to central axis X; with the extension being radiallyoutward in extension from adjacent end 4 in a direction toward end 3.

Typically, an angle (acute angle) of extension of the plurality of outerpleat tips 11 t (relative to a plane perpendicular to central cartridgeaxis X in a direction of extension from end 4 toward end 3) is at least1° larger, typically at least 2° larger and often at least 4° larger,than an analogous acute angle of extension of the plurality of innerpleat tips 10 t relative to the same plane perpendicular to the centralcartridge axis X and also in extension from adjacent end 4 in adirection toward end 3. Typically, end 22 is an end of the media support20 engaged by end 4 of the media. End 21 is an end remote from end 22,in the direction of cartridge end 7 and media end 3. The end 21 willtypically be positioned closer to media end 3 than to media end 4, andtypically within 50 mm of end 3, usually within 40 mm of end 3, mostoften within 20 mm of end 3 and in many instances, within 10 mm of end3. In some instances, end 21 may be positioned at media end 3, but inthe example depicted, end 21 is recessed toward media end 4, slightly,from media end 3, as discussed below.

In FIG. 10, a side view of the media 2 in the configuration of FIG. 8 isshown. In FIG. 10, example dimensions are indicated as follows: AE=379mm; AF=124.7 mm. Of course the principles can be implemented in avariety of different sizes and different arrangements.

In the particular cartridge 1 depicted, FIG. 1, the media 2 is supportedby a frame arrangement 20, referenced generally as a media support. Themedia support 20 generally extends between media support first andsecond ends 21 and 22. Preferably, the media support adds relativelyminimally to the radial thickness or dimension of cartridge 1, near end7. Near end 7 (and support end 21) the cartridge 1 is depicted with ahousing seal member 25 thereon. In the example depicted, the housingseal member 25 comprises an o-ring 26 configured to form a radially(outwardly) directed, seal with a (surrounding) housing component,during installation.

Typically, a largest radial dimension of width, indicated generally orby dimension X, FIG. 1A, of the cartridge 1, at a selected locationwithin 50 mm of media end 3 and cartridge end 7, is a radial dimensionadjacent a largest radial reach of the seal member 25. Typically, thislocation is within 40 mm of media end 3 and cartridge end 7, usuallywithin 30 mm of media end 3, and cartridge end 7 and most preferablywithin 15 mm of cartridge end 7.

Referring to FIG. 1A, it is noted that for the example depicted, at end3 a portion of the media 2 extends axially beyond end 21 of the support20. This optional extension, which is usually no more than 10 mmtypically no more than 5 mm, sometimes no more than 3 mm, and which canbe 2 mm less, for example 1 mm or less, but usually at least 0.5 mm, isan optional extension that can provide advantage. In particular, itcreates a flexible media tail region that can assist in providing asecondary seal adjacent the end of a support on which the cartridge 1can be mounted during typical use and also potentially against anadjacent end of the housing. Thus, referring to FIG. 1A, typically atend 3, the media 2 has an end tip 3 t that is not directly radiallyengaged by any portion of support 20 and is not embedded with any endcap material or similar material, but rather is a “free end tip 3 t.”

Typically, the widest portion of the cartridge 1, in a radial direction,adjacent, but typically spaced from tip 3 t, by no more than 20 mm, atend 3, and at a location of the seal 26, has an overall width dimensionof no greater than 20 mm, typically no greater than 15 mm and often nogreater than 12 mm. This, again, is the dimension indicated in FIG. 1Aat X, and is meant to refer to a dimension without distortion of seal 25by sealing engagement with structure. It may be referred to as theundistorted cartridge radial width dimension adjacent the housing seal.This dimension X, FIG. 1A, is usually at least 5 mm less than the pleatdepth adjacent end 14, typically at least 10 mm less, sometimes at least15 mm less.

The inner pleats 10 are characterized herein as relatively sharp. Thisis because the pleat tips 10 t adjacent end 4 are typically quite sharpin definition, not widely rounded. The inner pleats 10 may be relativelywide themselves, for example, with sides 10 a, 10 b diverging at anangle of at least 30° typically at least 40° for example 40°-70° inextension from the inner pleat tips 10 t at a location adjacent end 4.

Referring to FIG. 1A, the support 20 includes a seal support ring, endring (seal end ring) or seal support member 27 adjacent end 21; the sealsupport member 27 defining a groove 27 g for receipt of seal such aso-ring 26, therein. It will typically be the portion of the end member27 that defines the groove 27 g that provides for the widest depthdimension X, FIG. 1A, in combination with the seal 26, adjacent end 7 ofthe cartridge.

Referring again to FIG. 1, the support 20 preferably not only providesfor seal support, at region 27, but also provides for radial support ofthe media 2. Thus, the support 20 includes a longitudinally extendingmedia support region 29 that extends between support ends 21, 22.

With respect to detail concerning the example media support 20 depicted,attention is directed to FIG. 5. Of course variations in structure canbe made, as will be understood from the following.

In FIG. 5, the example support 20 is depicted independently of the media2 and seal member 25. With respect to FIG. 5, it is noted that in atypical approach to assembly in cartridge 1, discussed below, thesupport 20 is not made independently of the cartridge 1. That is,typically, the support 20 is injected molded onto the media 2, for atypical approach to manufacture of cartridge 1. Such a support 20 willsometimes be characterized herein as “molded-in-place” or by similarterms. The view of FIG. 5, which shows features of the support 20independently of the media 2, allows for an understanding of certain,selected, preferred support 20 features. It is also noted that some ofthe techniques and advantages described herein can be obtained in anarrangement in which the support is not molded-in-place on the media 2,but rather is separately formed and then is attached to the media 2 toform a cartridge.

Referring to FIG. 5, the support 20 can be seen as including alongitudinal support section 29 comprising a plurality of longitudinalribs 30 in extension between ends 30 a, 30 b. The ribs 30 are spaced,radially, around a central axis X, FIG. 1. Typically, the ribs 30 extendfrom adjacent end 4 of the media to a location at least 50% of adistance toward the first end 3 of the media, usually at least 75%,typically at least 80% and often at least 90% of this distance.

Referring to FIG. 5, ends 30 a of the ribs 30 are generally positionedadjacent end or end region 21 of support 20. The opposite ends 30 b aregenerally positioned adjacent end 22. In the example depicted, the ribs30 are straight in extension between the ends 30 a, 30 b, becausepreferably they are configured to engage and extend along outer pleattips 11 t. When this is the case, the number of ribs 30 will typicallycorrespond to the number of outer pleats 11, although alternatives arepossible. Also, typically the ribs 30 will be radially evenly spacedaround central axis X, since typically the pleats 11 will also besimilarly spaced. Alternatives are possible. Engagement of the ribs 30with the pleats 11 and pleat tips 11 t (and with the ribs 30 extendinggenerally straight in extension between end 30 a, 30 b, with even radialspacing around axis X) will typically be preferred as it helps securethe media 2 and the pleats 11 in a preferred configuration, of the typedescribed. (Preferably there are no ribs 30 that are not positionedalong a pleat tip 11 t).

The cartridge 1, of FIG. 1, using support 20, is provided with a pleatshape or spacer arrangement not viewable in FIG. 1, but viewable in FIG.5 at 35. In general, the pleat spacer arrangement 35 is an arrangementthat comprises relatively rigid projections that extend radially towardaxis X and into spaces between the various ones of the outer pleats 11(FIG. 8), to help ensure proper pleat spacing/shape. This helps protectthe media 2 against pleat collapse, etc. For the particular exampledepicted, the pleat spacer arrangement 35 is provided as an outside orexterior spacer arrangement, with the projections extending between theouter pleats 11, at a location around an outer perimeter of the media 2.

The terms “exterior” or “outside” when used in the context ofcharacterizing spacer arrangement 35, is meant to indicate that thespacer arrangement is generally configured around an outside of themedia 2, with pleat spacing portions positioned between outwardlyextending pleats 11. The terms “exterior” and “outside”, then, refer tothe fact that the pleat spacer 35 is generally around an exterior of themedia 2, not an interior.

Referring to FIG. 5, and in general in reference to pleat spacerarrangement 35, the assembly includes at least one intermediate pleatspacer 36. The term “intermediate” in this context, is meant to refer toa pleat spacer 36 positioned axially spaced (i.e. in the direction ofaxis X) from each of ends 22 and 21 of support 20, and spaced from eachof ends 3, 4 (FIG. 8) of the media 2. The particular pleat spacerarrangement 35 depicted, includes three, spaced, intermediate pleatspacers 36, 37, 38. In more general terms, the pleat spacing arrangement35 will typically include at least one, and usually a plurality of,intermediate pleat spacers (36, 37, and 38). The typical number will beat least two and usually there will not be more than 5; the numbertypically being related to a length of the cartridge 1 and the nature ofsupport preferred for the media 2, for the intended use.

Referring to FIG. 5, intermediate pleat spacer 36 is configured tosurround an outer (or exterior) surface 20 of the media 2; and, to havea plurality of spaced radial projections 36 r that extend radially totips 36 t in a direction toward the central axis X and which extend,generally, between outer pleats 11, in the assembled cartridge 1,FIG. 1. Similarly, intermediate pleat spacer 37 comprises a plurality ofspacers 37 r directed, generally, radially inwardly to tips 37 t, i.e.,toward central axis X, and positioned between outer pleats 11. Finally,pleat spacer 38 comprises a plurality of radial extensions 38 r thatextend generally radially inwardly to tips 38 t towards the central axisX, and which are configured to be positioned between adjacent ones ofouter pleats 11.

It is noted that in the example cartridge 1 depicted, the amount ofextension (or radial dimension) toward axis X inwardly of tips 38 r isless than tips 37 t, which is less than tips 36 t. The reason for thisis that for the example cartridge 1 depicted, the pleat depth of themedia 2 decreases as it extends toward end 21 from 22 as discussed abovein connection with FIGS. 8-10.

Still referring to FIG. 5, typically ribs 30 and pleat spacers 36, 37,38, are molded integral with one another, for convenience. A particular,convenient, assembly approach is described further herein below.

The particular configuration of the pleat spacers 36, 37, 38 (i.e.,spacer arrangement 35 generally) is generally a matter of choice for theapplication of concern and the methods of concern. Typically, thepattern defined by the spacers (36, 37, 38) will correspond to thepattern intended for the media 2, with respect to the definition of theperimeter configuration. Whether or not each one of the spacers (36, 37,and 38) is in a plane perpendicular to central axis X is a matter ofchoice, in part depending on the particular approach to manufactureused. Whether or not the upper and lower surfaces of the spacers 36, 37,38 (upper and lower in this context referring to the extension of FIG.5) are planar, is also a matter of choice depending on the method ofmanufacture chosen. The particular configuration depicted in FIG. 5 isconvenient and effective, but alternatives are possible.

The spacing of the pleat spacers 36, 37, 38 from one another, and fromadjacent ones of ends 21, 22, is a matter of choice for accomplishingthe desired support for a given system. Typically, spacers 36, 37, 38will be spaced relatively evenly from adjacent ones of the spacers 36,37, 38 and relatively evenly from opposite ends 21, 22. Thus, forexample, with three spacers each could be spaced from an adjacent spacerby about 20-30% of the distance between the ends 21, 22.

Still referring to FIG. 5, at end 22, which is an end of support 20 thatwill be positioned adjacent end 4 of the media 2, FIG. 1, the support 20(in cartridge 1) includes an end piece 40. End piece 40 will sometimesbe referred to as a media end piece or as a media support end piece orby similar terms. The end piece 40 is generally positioned to extendacross an end of the media 2 at end 4, i.e., an end remote from theoutlet end 7 of the cartridge.

In general, the end piece 40 interiorly closes ends of the pleats 10, 11adjacent media end 4. When, the support 20 is molded-in-place, it istypically formed with end 4 of the media 2 embedded in material fromwhich the end piece 4 is formed. When it is said that the end piece 40“interiorly closes” the ends of pleats 10, 11, it is meant that theclosure is at least on an inside of the media 2, i.e. at a downstreamside of the media.

The end piece 40 can be an “open” end piece or a “closed” end piece. Bythe term “closed” in this context, it is meant that the end piece 40would include no open central aperture therethrough, in communicationwith an open interior 2 i of the media 2 (interior 1 i of the cartridge1), FIG. 1; i.e. there would be no aperture or any aperture presentwould be plugged closed in some manner. For the particular cartridge 1depicted, the preferred end piece 40 is “open,” in that there is acentral aperture 40 a therethrough, that communicates with the openinterior 2 i of the media 2 (i.e., open interior 1 i of the cartridge1), FIG. 1. When the cartridge 1 is installed for use, a portion of thehousing can optionally project through aperture 40 a, stabilizing thecartridge 1. Also, when the cartridge 1 is installed for use, theoptional aperture 40 a often be sealed closed to avoid a leak path withrespect to operation of the cartridge 1.

Referring to FIG. 5, the end piece 40 for the example embodimentdepicted, has an outer perimeter 40 p comprising a plurality ofalternating radially inwardly extending sections, gaps or recesses 40 iand outwardly projecting fingers, flanges or sections 40 o. The recesses40 i are typically positioned in axial overlap with end of flutes alongan exterior or upstream side of the media 2. While alternate perimeterdefinitions are possible, this definition of alternating outwardprojections 40 o and inwardly projecting recesses or sections 40 i isdesirable, because it allows for a longitudinal (axial) flow of gases(e.g., air) in a direction along the outer surface 2 o (FIG. 8) of themedia 2, between outer pleats 11, adjacent end 4 and between projections40 p. This provides for a convenient, less restrictive, gas flow.Alternative shapes for end piece 40 are possible, however.

Typically, the number of projections 40 o and recesses 40 i correspondsto the number of pleats 11.

Typically, each of the recesses 40 i projects radially inwardly towardcentral axis X, a distance of at least 10 mm (relative to theprojections 40 p) usually at least 15 mm and often an amount within therange of 20-40 mm. Also typically the recesses 40 r project towardcentral axis X, a distance of at least 25%, usually at least 30%, andoften an amount within the range of 40-60%, inclusive, of the distancebetween outermost parts of the projections 40 p and the central axis X.Typically, the projections 40 p are spaced apart (at outermost tips) byat least 30 mm, usually at least 35 mm; and, by an angular definitionaround central axis X of at least 30°, typically at least 40°.

The depth of the recesses 40 i characterized in the previous paragraphis not critical, but does provide for advantage. In particular, itensures a good, open, area along a longitudinal (axial) flow paththrough end piece 40 down in between outer pleats 11 during operation,which is a favorable flow path for managing restriction issues.

Referring to FIG. 5, end piece 40 generally includes a central region 45that extends across an otherwise open interior end of the media 2 at end4, FIG. 1. Referring to FIG. 1, central region 45 is defined by an innersurface 45 i and outer surface 45 o; the inner surface 45 i being thesurface that faces an interior 1 i the cartridge 1 (and media end 3,cartridge end 7 and support end 21); and, the exterior surface 45 obeing an opposite surface.

In FIG. 1B, an enlarged fragmentary view of a portion of the cartridge1, FIG. 1, is provided, for some convenient inspection on end piece 40.In general, the aperture 40 a, referenced above, extends through centralregion 45, in communication between inner surface 45 i and outer surface45 o.

Within the interior surface 45 i, end member 40 (i.e., central portion45 of cartridge 1 generally) includes a receiver recess 46 r. Thereceiver recess 46 r generally comprises a recess in a projection 46projecting in a direction (of extension of central axis X) away from end7 of the cartridge 1, FIG. 1. It is not, however, meant that theprojection 46 necessarily extends parallel to central axis X. Typically,the central recess 46 r is defined by a wall symmetrical in extensionaround central axis X, although alternatives are possible. The receiverrecess 46 r is defined by a wall or projection 46 having surface 46 pand is configured to optionally to receive, projecting therein,structure of certain preferred types of housings with which thecartridge 1 can be used, as discussed below.

It is noted that the optional aperture 40 a is provided in communicationwith recess 46 r, with central axis X passing therethrough. When theoptional aperture 40 a is used, this will be a typical position. Incertain applications, a portion of a housing that optionally projectsinto recess 46 r will also be configured to project completely throughaperture 40 a, in a preferred manner, discussed below.

Referring to the wall 46 p of surface 45 i that defines the recess 40 a,it is noted that for the example depicted, FIG. 11B, surface 46 p isgenerally frusto-conical or truncated; reducing in inner perimetercross-dimension definition (typically diameter) in extension in ageneral direction of axis X away from media end 3 and support end 21. Atypical configuration will have such a slant or frusto-conical shape toit, with the side wall 46 p extending, generally, radially inwardly atan angle of about 85°-99.5°, inclusive, relative to a planeperpendicular to central axis X, in extension away from media end 3 andsupport end 21. Alternatives are possible.

Referring to FIG. 1B, it is noted that the aperture 40 a in theparticular example depicted, has been fitted with (i.e. is lined with) aliner or grommet 48. The particular liner or grommet 48 depicted,includes an optional central aperture 48 a therethrough, correspondingin part to aperture 40 a. The grommet 48, when used, will typicallycomprise a resilient, seal-type, material.

Typically, the recess 46 r extends, axially, a distance of at least 15mm usually at least 20 mm, often 20-40 mm, inclusive, in extensionbetween an innermost end 46 i and on outermost end 46 o, FIG. 1B. Theliner or grommet 48 will typically extend, axially, at least 10% of anaxial extension (extension in the direction of axis X) of recess 46,typically an amount within the range of 20-40%, inclusive, of thisextension.

Referring to FIG. 1, for the particular cartridge 1 depicted, the outersurface 45 o of the end piece 40, includes an optional outer receivinggroove 50 therein. The outer receiving groove 50 is a groove that isopen in a direction away from media end 3 and extends generally towardend 7 from regions adjacent end 8. The groove 50 is typically andpreferably at least 5 mm deep in axial extension from immediatelyadjacent portions, typically surrounding portions, of end member 40,typically at least 8 mm deep and often 8-20 mm, inclusive, deep.Typically, the groove 50 is at least 5 mm wide, typically at least 6 mmwide and often 6-30 mm, inclusive, wide, in extension between radiallyinner surface 50 i and radially outer surface 50 o thereof. Usually itis not more than 20 mm wide. Typically the radial inner surface 50 i isdefined by a wall 52, which, along an interior surface thereof, definesrecess 48. Typically, the wall 52 extends axially in a direction awayfrom end 7 to a location further than an end 4 of the media, typicallyat least 5 mm further and often at least 10 mm further. In the exampledepicted, the wall 52 defines a tip 52 t, which also defines aperture 40a discussed above.

The optional receiving groove 50 is typically and preferably configuredto mate with portions of a main filter cartridge in an air cleanerassembly.

Attention is now directed to FIG. 5 and to optional projectionarrangement 55 on outer surface 40 x of end piece 40. Optionalprojection arrangement 55 is typically relatively narrow in maximumwidth (typically not more than 10 mm) and projects in a direction awayfrom surrounding portions of surface 45 o, a distance of at least 0.5mm, usually at least 1 mm, and typically not more than 10 mm. Theparticular optional projection arrangement 55 depicted is a continuousring 55 r, but alternatives, such as segmented rings, are possible. Theprojection arrangement 55 comprises an optional contact region forengagement with the main filter cartridge, in selected uses of thecartridge 1.

Attention is now directed to FIG. 7, a side elevational view of support20, with attention particularly directed at end 21. Around end 21,spaced gussets 57 are shown slanted outwardly to rim 27 r of groove 27g. The gussets 57 facilitate positioning an o-ring in groove 27 g. Inparticular, the o-ring can be pressed against the gussets 57, and then,with pressure toward end 22, the o-ring will spread and eventually snapover rim 25 r and into groove 27 g.

In FIG. 1, an example dimension is indicated as follows: AA=392.6 mm. Ofcourse, alternate dimensions can be used.

In FIG. 2, an end view of cartridge 1 is, shown, taken, generally,toward end piece 40. An example dimension is provided as follows:AB=135.3 mm diameter.

In FIG. 3, an end view taken toward end 3 is depicted. In the schematicdepiction, recess 46 can be viewed.

In FIG. 4, an exploded view of the cartridge 1 is depicted. The variouscomponents as previously described and viewable include: media 2,support 20, grommet 48 and o-ring 26.

In FIG. 7, a cross sectional view of frame member 20 is shown. Exampledimensions are indicated as follows: AC=389.2 mm; and, AD=133.1 mm.

From review of FIGS. 1 and 1A, again, it can be understood that in theexample arrangement depicted, the media at end 3 projects axially beyondend 21 of support 20. The amount of this extension, when present, willtypically be no more than 10 mm typically no more than 5 mm and often atleast 0.5 mm, sometimes at least 1 mm. The portion of media end 3 thatextends beyond any structural support of support 20, i.e., beyond end 21of support 20, will sometimes be referred to as a “seal end” or “endtail” and by the designator 3 t, FIG. 1A. This seal end or tail 3 t canprovide a number of advantages. First, being flexible, it can push downinto and against structure of the housing adjacent (both axially andradially) end 3 of the media. It, thus, can help provide secondarysupport to sealing, in addition to the primary cartridge seal 26.Further, this seal end or tail 3 t can provide a wiping effect as thecartridge 1 is installed/removed.

Possible variation in the cartridge 1 can be understood by considerationof FIGS. 1C, 1D, 1E and 2A. In FIG. 1E, the cartridge analogous tocartridge 1 is depicted, except having no optional projection 55 (FIG.1B) thereon; and, having a variation in a grommet 48 v, from grommet 48.In FIG. 1C, like reference numerals are used to FIG. 1, generally,except for designation of the grommet, which in FIG. 1C is indicated at48 v. In FIG. 1C, example dimensions are indicated as follows: ZQ=12.2mm; ZS=138.7 mm; ZR=392.6 mm.

In FIG. 1D, an enlarged fragmentary view of an identified portion ofFIG. 1C is provided. This is the region adjacent seal 26, discussedabove in connection with FIG. 1A. In FIG. 1D, example dimensions areindicated as follows: YH=5.5 mm; YI=7.5 mm; YJ=9.1 mm. In FIG. 1E, anenlarged fragmentary view of an identified portion of FIG. 1C isprovided. From inspection of FIG. 1E, it can be again seen that thecartridge 1 depicted does not have the optional projection 55 r, FIG.1B. It can also be seen that the alternative gusset 48 v includes outerrings 48 r, embedded in structure from which support 20 is formed, as aresult of manufacture in accord with an approach discussed below. Theoptional rings 48 r are not shown in the gusset 48, FIG. 1, but can beused with that embodiment. In other manners, the features of FIG. 1E aregenerally analogous to those discussed and described in connection withFIG. 1B. In FIG. 1E, example dimensions are indicated as follows:ZV=24.6 mm; ZT=47 mm; and, ZU=18.4 mm.

In FIG. 2A, an end view analogous to FIG. 2, but of the cartridge ofFIG. 1C without the optional projection 55 r is depicted. Other featuresare generally analogous to those discussed above in connection with FIG.1, and shown in FIGS. 1C and 1D. In FIG. 2A, example dimensions providedare indicated as follows: ZL=10 mm radius; ZM=45°; ZN=1 mm radius;ZO=61.5 mm; and, ZP=123 mm.

II. Example Manufacture of the Filter Cartridge of FIGS. 1-10

A variety of techniques can be used to construct a cartridge havingfeatures in accord with the present disclosure. The preferred cartridge1 configured as depicted in connection with FIGS. 1-10, and using acartridge support 20 as described to support media as configured inFIGS. 8-10, will typically be made by preforming media into the shapeshown described in connection with FIG. 8 and then (injection) moldingthe support 20 in place, onto the media. This can be done with the moldconfiguration that supports the media 2 in the desired configuration,while directing the polymeric material appropriately.

Typically and preferably, with techniques described herein, and in whichthe support 20 is molded-in-place, preferably the injected material forforming the molded-in-place support 20 is provided exteriorly of themedia 2. That is, preferably at locations extending along the length ofthe media 2, except immediately adjacent end 4, the resin material isnot injected in the interior 2 i of the media 2, but only along theexterior 2 o. The resin will penetrate into the media somewhat, butpreferably along most of the lengths of the pleats 11 it does not extendradially completely through the media 2 enough to project radiallyinwardly from the media 2 except, in some instances, in the regionimmediately adjacent end 4, and then, as limited as reasonable whileobtaining good adherence/seal.

Typically and preferably, a single shot mold approach is used, toaccomplish construction of the entire support 20 in one injection stepin the molding. The support configuration depicted in FIG. 5, withsupport features as described, is configured to allow for this.

As discussed herein above, the support 20 can be provided with a grommet48 (or 48 v) positioned at an end thereof. Typically, when the support20 is molded-in-place, for example using an injection molding operationas described, the grommet 48 (or 48 v) is prepositioned in the mold, sothat as the molding occurs, the grommet 48 (48 v) becomes secured inplace.

The material used for the support 20 will typically be a material havingsufficient strength to provide the desired support to the media 2, inuse. An example would be a thermoplastic, such as a polypropylene orpolyethylene. Alternatives are possible.

For the grommet 48 (or 48 v), typically, a thermoplastic elastomer (tpe)will be used. A typical grommet will comprise a resilient materialcapable of forming a seal and may, for example, be formed from a resinto have a hardness of at least 30 Shore A, typically at least 40 ShoreA, for example 50-80 Shore A. Alternatives, of course, are possible.

The material chosen for the media is a matter of choice, for the flowcharacteristics and filtering characteristics and filteringcharacteristics desired. Filter media of a type typically used in safetycartridges can be used.

The media will include a longitudinal seam therein. The seam can beformed with sonic welding, heat welding, or adhesive, or it can beconfigured to be sealed by the resin forming the frame structure, ifdesired.

III. An Example Filter Assembly Using Cartridge 1 as a Safety Filter A.An Example Filter Assembly and General Features, FIGS. 11-13B

In FIGS. 11-13B, a filter assembly (for example an air cleaner) havingadvantageous features and using a secondary or safety cartridge inaccord with cartridge 1, discussed above, is depicted. Many of thefeatures are variations of those described in one or both of WO2009/014986 and WO 2012/116314, referenced above and incorporated hereinby reference. Advantageous variations, however, are provided asdiscussed.

Attention is first directed to FIG. 13. In FIG. 13, a gas filterassembly 100 configured as an air cleaner assembly, is depicted incross-sectional view. The filter assembly 100 comprises a housing 101having, operably positioned therein, a main or primary filter cartridge102 and a secondary or safety cartridge 1 in accord with the presentdisclosure.

In general, air to be filtered flows into housing 101 through gas (air)flow inlet arrangement 105. The air is directed through primary or maincartridge 102, with “out-to-in” flow and then through a secondary filter1, with a “out-to-in” flow. The filtered gas (air) exits housing 100through outlet flow arrangement 106.

Attention is now directed to FIG. 11, in which the housing 101 isdepicted without the primary filter cartridge 102 and secondary orsafety cartridge 1 installed. Referring to FIG. 11, the housing 101comprises a housing body or base section 109 and an access cover 110.The housing body or base section 109, in the example depicted, definesan open end 109 a and an opposite end 109 b. The open end 109 a is anaccess end, over which the access cover 110 is removably positioned. Theaccess cover 110 is shown removably secured in place by latcharrangement 111.

In the example assembly depicted, the inlet 105 and outlet 106 arepositioned on the body section 109, although alternatives are possible.Positioned on the access cover 110, is an optional evacuator outlet 114,closed by an evacuator valve arrangement 115. Some dust and water can beejected from housing 101 through evacuator outlet 114 and valve 115, inuse. Such evacuator arrangements are sometimes referred to as“precleaners” and are used in a wide variety of air cleaner systems.When an air cleaner assembly uses such an optional precleaner, it issometimes referred to as a “two-stage” air cleaner, the first stagebeing the precleaner and the second stage being represented by thefilter cartridge arrangement.

Still referring to FIG. 11, as gas flow (i.e. air flow) enters throughinlet or inlet tube arrangement 105, it is directed into optionalcyclonic ramp arrangement 117, by which it is directed into a helical orcyclonic flow around central axis X. This helps direct some of the waterand/or particulate material contained within the air flow, intoevacuator arrangement 114, before that material impinges on the primaryfilter cartridge 102, FIG. 13. To facilitate such a cyclonic movement ofthe air, preferably inlet arrangement 105 is configured with an air flowinlet direction represented by an axis A that is tangentially directedrelative to sidewall 109 s.

To facilitate precleaning, the housing 101 includes a shield section 118projecting toward access cover 110 from end 109 b, and an optionalsecond shield section 119 projecting toward and 109 b and outlet 106,from access cover 110. These optional (but preferable) shield sections118, 119 will be positioned around opposite ends (respectively) of themain filter cartridge 102, FIG. 13, to help isolate flow of water and aportion of particulate material from inlet 105 to ejector or evacuatoroutlet 114, to advantage.

Still referring to FIG. 11, access cover 110 includes an end wall or end110 e, having an optional central projection 120 thereon, that projects,generally, toward end 109 b and outlet 106. In the example depicted, theprojection 120 is positioned with central axis X extending therethrough,which will be typical.

The central projection 120 can have a variety of specific configurationsand shapes. It can be configured as a ring, be solid or hollow, or itcan have a cross-sectional definition defined by fins or otherstructures.

With respect to selected features of projection 120, attention isdirected to FIG. 11A. Attention is particularly directed to end 120 e,of access cover or central projection 120; end 120 e being an end remotefrom end wall 110 e. Optional but preferable features at end 120 e ofinterest include the following. First, the access cover 110 includesthereon, a projection 123 which, in the example depicted, comprises aring projecting in the general direction of axis X away from end 110 eand toward end 109 b. The projection 123 is sized and configured toengage width cartridge features as discussed below.

The ring 123 surrounds an optional central recess or receiver 124 inprojection 120. The recess 124 is preferably configured to receive,projecting therein, selected portions of the housing 101 and cartridgearrangements as discussed below. Typically, the recess 124 projects atleast 10 mm usually at least 15 mm and often an amount within the rangeof 20-40 mm, inclusive, toward end 110 e from tip 123 t of projection123.

Still referring to FIG. 11A, it is noted that ring 123 is typically atleast 5 mm long in extension from a surrounding portion 125, ofprojection 120 to tip 123, usually at least 10 mm long and often has alength within the range of 10-25 mm.

Referring back to FIG. 11, the housing 101 includes a central cartridgesupport 130 therein. The central cartridge support 130 is positioned inextension from adjacent wall 109 b toward access cover 110. The centralcartridge support 130 generally includes a base end 131, a poroussidewall 132 and a cartridge support end 133. The base end 131 ispositioned adjacent end 109 b, and includes a gas flow aperture 131 atherethrough providing gas flow communication with outlet 106. Thecartridge support end 133 is remote from wall 109 b, and is directedtoward access cover 110.

The central cartridge support 130 can be formed integral with aremainder of housing section 109. For the example depicted, however, thecentral cartridge support 130 comprises a separately formed piece whichis snap-fit in place by a snap fit arrangement 131 x, FIG. 11B, inengagement with a surrounding portion 135 of housing section 109. Thesurrounding portion 135 includes a flange 135 f, which surrounds aportion of central cartridge support 130.

It is noted that in some instances, the central cartridge support 130can be constructed to be removable from the housing section 109 onceinstalled. However, typically and preferably the cartridge support 130is non-removable from housing section 109, either by having been formedintegrally therewith (for example by being molded integral with otherportions of the section 109) or by having been installed with a snap-fitconnection not readily disconnected once established. Preferably thesupport 130 does not include any media, independent of a serviceablecartridge 1, 102.

Typically, the central cartridge support 130 is independent andseparable from any filter cartridge positioned within the assembly 100during use. That is, typically the central cartridge support 130comprises a portion of the housing 101, and remains with the housing 101during servicing of the cartridges 1, 102.

Referring to FIG. 11B, it is noted that flange 135 f projects towardaccess cover 110, to tip 135 t. The flange 135 f defines a sealingflange for the system 100 depicted. In particular, the outer surface 135o of flange 135 will form a seal surface for the main filter cartridge102; and, an inner surface 135 i of flange 135 will form a seal surface4 for the safety cartridge 1. Although alternatives are possible, thisis particularly convenient for installation of the cartridges 102, 1.

The support 130 is provided with an open interior 130 i surrounding axisX and positioned in air flow communication with outlet 106. Thus, aftergases have been filtered by the main filter 102 and safety 1, they willpass into interior 130 i and outwardly from housing 109 through outlettube 106. It is preferred that the outlet 106 (and end 131 a in support130) have as large a cross-sectional area as reasonably possible, so asto avoid undesirable additional restriction to air flow through housing101. Selected features of the present disclosure facilitate this, asdiscussed below.

At outlet 106 optional pressure tap 106 t, FIG. 11B, is provided,facilitating connection of a restriction indicator or pressure monitorin a typical conventional manner.

In FIG. 11A, support end 133 of central cartridge support 130 can beseen in detail. The support end 133 is the end of support 130 remotefrom base 131 and sidewall 109 b, and comprises an optional outer ringor shoulder 138 and a central projection 139. In the example depicted,the central projection 139 is positioned on central axis X. While thisis typical, alternatives are possible.

Positioned between shoulder 138 and central projection 139 at a locationsurrounding the central projection 139, the cartridge support end 133 ofcentral cartridge support 130 includes a receiving groove, recess orreceiver space 140. Receiver space 140 is, typically, at least 5 mmdeep, typically at least 8 mm deep, for example 8-25 mm deep, inclusive,in extension along the direction of axis X toward outlet 106 from asurrounding portion of the end 133, typically shoulder 138. The recess140 is typically at least 5 mm wide, for example 8-20 mm wide, and notusually more than 25 mm wide, in extension thereacross, between sidewall140 w and projection 139. Typically, the outer wall 140 w of recess 140is positioned spaced radially at least 10 mm radially inwardly from anouter portion of perimeter of support 130.

Still referring to FIG. 11A, it is noted that projection 120, and inparticular projection end 123 is typically, and optionally, sufficientlylong to at least start to extend into recess 140, when access cover 110is positioned on housing base 109.

Still referring to FIG. 11A, attention is now directed to centralprojection 139.

The central projection 139 includes, as it extends toward access cover110, a shaft or base 144 extending to a remote end or tip 145. Betweenbase 144 and tip 145, the projection 139 includes an optional butpreferable neck section 146. The optional neck section 146 is a narrowedsection in projection 139. Thus the projection 139, typically andpreferably has a tip 145 of large cross-sectional dimension (typicallydiameter) than another portion, i.e. the neck section 146, that ispositioned between the tip 145 and a base 144. This optionalconfiguration can provide for advantage, as discussed further below.

Referring to FIG. 11B, attention is directed to recess 150 r betweencentral cartridge support 130 and flange 135 f. The recess 150 r is arecess into which an end of a safety filter cartridge 1, discussedbelow, extends during installation. It is, in particular, a recess intowhich an end 7 comprising media end 3, FIG. 1, projects. It is notedthat the recess 150 r is relatively narrow in radial dimension,typically its widest dimension being no greater than 30 mm, preferablynot greater than 25 mm, usually not greater than 20 mm, sometimes 15 mmor less. A reason for this is that it is preferable that radialdimension in the region of section 131 of central cartridge support 130,of the cartridge 1 take up as little radial dimension as reasonable soas to facilitate flow through filter assembly 100 with without undueaddition to restriction. This is discussed below.

The recess 150 r will sometimes be referred to herein as a safetycartridge end receiving recess 150 r, or by similar terms. In a typicalembodiment, it will be formed between the flange 135 f and a region ofcentral cartridge support 130 adjacent end section 131.

Attention is now directed to FIG. 12, in which the housing 101 isdepicted with the safety cartridge 1 fully installed, but without theprimary filter cartridge 102 positioned. It can be seen that the safetycartridge 1 is installed by being pushed over the central cartridgesupport 130. Selected portions of the interaction among the cartridge 1,central cartridge support 130 and housing 101 are discussed inconnection with FIGS. 12A and 12B, each of which is an enlargedfragmentary view of a portion of FIG. 12.

Referring first to FIG. 12A, an interaction between end 7 (and media end3) of safety cartridge 1 and recess 150 r can be seen. First, it can beseen that as a result of not being pleated (i.e., being of very limitedor no pleat depth) near end 3, the cartridge 1 will fit in therelatively narrow recess 130, with seal 26 engaging inner wall 135 i offlange 135 f, to form a radially (in the example outwardly) directed,housing seal that is releasable. Further, it can be seen that free endor tip 3 t of the media 2, i.e. a portion of media 2 not embedded in anend cap and not surrounded by media support 29 can be pushed to, or nearto, an end of recess 150 r, and will tend to pick up and pull (wipe) outof the recess 150 r particulate material that may migrate into thisregion during use and/or servicing.

It can also be seen by referring to FIG. 12A, that due to the verynarrow construction of the cartridge 1 in radial dimension at seal 26, anarrow recess 150 r can be used to advantage, to avoid undesirableaddition to restriction from the size of outlet 106, and outlet end 131a of central cartridge support 130, while (at the same time) allowingmaximal radial width within housing 109 for the main filter cartridge102, as discussed below.

Indeed, typically the maximum radial width of recess 150 r for insertionof end 7 of cartridge 1 therein, is at least 5 mm smaller, usually atleast 10 mm smaller, and sometimes at least 15 mm smaller than a maximumpleat depth of the media 2, of cartridge 1, adjacent end 4, FIG. 1.

Attention is now directed to FIG. 12B, an enlarged fragmentary viewdepicting an interaction between the cartridge 1 and the centralcartridge support 130 at support end 133. In particular, cartridge 1 canbe seen positioned with central recess 46 r receiving, projectingtherein, central projection 139 on central cartridge support 130. Forthe particular example depicted, the central projection 139 projectscompletely through recess 46 r (and aperture 40 a) and optional grommet48 v, with tip 145 projecting through aperture 40 a. The optionalgrommet 48 v is shown engaging the central projection 139 therearound,in the particular example by engagement at least with neck region orsection 146. In the example depicted, the optional grommet 48 is shownsecured within end projection 46 by having been positioned in a mold andhaving section 46 molded thereto, with physical connection provided bygrommet rings 48 r, FIG. 1E.

Also, referring to FIG. 12B, it can be seen that projection 45 p on endpiece 20 projects into receiver 140 on the central cartridge support130. Further, it can be seen that projection 123 on the access cover 110projects into recess 50 on secondary or safety cartridge 1.

In the example depicted in FIGS. 12A and 12B, it is noted that thecartridge 1 does not include the optional projection 55 r, FIG. 1B,thereon. Of course, such a projection can be used to advantage, ifdesired. Advantages for such an optional projection 55 are discussedbelow.

In FIG. 12C, a view generally analogous to FIG. 12 is depicted. In FIG.12, some examples dimensions are indicated as follows: YC=354.6 mm;YD=115.8 mm; YE=65.6 mm; YG=539.7 mm; YF=423.3 mm.

Attention is now directed to FIGS. 13, 13A and 13B. Here, filterassembly 100 is depicted with both the primary filter cartridge 102 andsecondary filter cartridge 1 in place. Referring first to FIG. 13, theprimary filter cartridge 102 can be seen as having opposite ends 102 a,102 b, with media 150 extending between opposite first and second mediaends, 151, 152, corresponding to cartridge ends 102 a, 102 brespectively. The media 150 will typically be pleated, althoughalternatives are possible. In the example depicted, the media 150 has agenerally conical or frusto-conical outer perimeter 150 p defined byouter pleat tips with outer perimeter 150 p decreasing incross-sectional size in extension from end 151 to end 152. Typically,the extension is at a conical angle, i.e. an inward taper, of at least0.5°, typically not more than 5°, and often within the range of 1°-5°.

Referring to FIG. 13B, the cartridge 102, includes, positioned on themedia 150 at end 151, and end cap or end piece 154. The particular endpiece 154 depicted, is molded-in-place, although alternatives arepossible. Typically, the end piece 154 when configured as shown, wouldbe molded from a material such as foamed polyurethane, that can alsooperate as a seal material as discussed below. Typically, the materialwill be molded to an as “molded” density of no greater than 0.32 g/cc,typically no greater than 0.24 g/cc, for example 0.16 g/cc-0.24 g/cc,and, will have a hardness, Shore A, of no greater than 20, typically nogreater than 18, and often within the range of 10-18, inclusive.

Referring still to FIG. 13B, end cap 154, which is at main cartridge end102 a, is shown with a central aperture 155 therethrough, which willserve as an “flow aperture” for main cartridge 102, in the example a gasflow exit aperture. In the example, the aperture 155 is defined by, andis surrounded by, housing seal region 156, which, in the exampledepicted, is a portion integral with a remainder of end cap 154. Sealregion 156, in the example depicted, is positioned and configured toform an inwardly directed radial seal around central axis X, andreleaseably in engagement with outer surface 135 o of flange 135 f.

Referring to FIG. 13, it is noted that an end 151 of media 150 is partof an end section of media that will project at least 10% usually atleast 20% and typically not more than 50% from media end 151 towardmedia end 152, while being surrounded by flange 118. This helps providefor desirable operation of the precleaner function in housing 101. Theflange 118 is preferably sufficiently large to still allow air flow to aregion surrounding end section 151, for good filtering operation. Thetapering of media 150 facilitates this.

Still referring to FIG. 13, it is also noted that flange 119 surroundsend section 152 of the media 150 adjacent end 150 b. Typically, itsurrounds the media 150 over a length of extension at least 5%,typically not more than 20% from end 152 toward end 151. Support 119provides a centering function for the cartridge 102, and can providesome protection for the cartridge 1. Additional protection for thecartridge 102 is provided by end margin or wrap 148, which surrounds themedia 150 adjacent end 152.

Still referring to FIG. 13, it is noted that the media 150 includes aninner perimeter 150 i, typically defined by inner pleat tips, whichtapers downwardly in extension from end 151 to end 150 b. Typically, anangle of extension of inner perimeter 150 i relative to axis X is thesame as the angle discussed above for perimeter 150 p. It is furthernoted that, for the example depicted, the cartridge 102 includes aporous inner liner arrangement 160 around which the media 150 ispositioned. This is typical, but optional.

Referring to FIG. 13B, attention is directed to recess 162 in end piece154. The recess 162 can be an artifact, from a mold stand-off for themedia 150, during manufacture of end piece 154. It also can be used as areceiver recess for an optional projection member (not shown) within thehousing end 109 b. Both functions can be provided by the recess 162, or,in some, systems two different recesses can be provided.

Referring still to FIG. 13B, projection arrangement 163 (on end piece154) is shown engaging end wall 109 b of the housing section 109. Theprojection 163 can, for example, be a continuous ring, segmented ring,or a plurality of bumpers, to provide for cushion engagement with endwall 109 b to advantage.

Referring again to FIG. 13, attention is directed toward end 152 ofmedia 150. At end 152, the cartridge 102 includes a second end cap orend piece 170. End piece 170 generally comprises: an outer ring section171, which is in axial overlap with end 152 of the media 150; and,central section 172, which projects inwardly into an open filterinterior 102 i of cartridge 102, from end 152 of the media 150 towardend 150 a. Typically, end piece or end cap 170 is closed, i.e. it has nocentral aperture therethrough, although in some applications,alternatives are possible. Typically, section 171 is molded-in-place,for example, from a material similar to, or in some instances harderthan, that used for end piece 154; with central section 172 preformed,for example from a rigid plastic and then secured in place during themolding of section 171. Alternatives are possible. The seal section 171can, optionally, include a projection 163 x, analogous to projection 163but positioned to engage access cover 110.

Attention is directed to FIG. 13A, with respect to selected features ofprojection 172. Projection 172 generally includes an outer sidewall 173and an end section 174. The end section 174 is defined by: an innersurface 174 i that faces toward the opposite end piece 154 from endpiece 170; and, an opposite, outer, surface 174 o.

In the outer surface 174 o, end 174 forms a receiving groove 177 thatsurrounds a central projection 178. The receiving groove 177 istypically at least 6 mm deep, usually at least 8 mm deep in deepestextension, from nearest surrounding portions 177 x of end 174. Theprojection 178 generally extends at least 10 mm, typically at least 15mm and often an amount within the range of 15-35 mm, inclusive, from animmediately surrounding portion of groove 177.

Typically, the projection 178 on the central section 172 comprises acentral projection directed away from the first end piece and whichterminates at an end remote from the media first end at a location thatis spaced from the media second end at least 15% of a distance from themedia second end to the media first end.

The groove 177 is typically at least 4 mm wide and usually not more than25 mm wide, between inner and outer sidewalls 177 i, 177 o.

Along the inner surface 174 i, the projection 178 defines a receiverrecess 178 r into which the central projection 139 (of the centralcartridge support 130) and the central projection 46 of the secondarycartridge 1 project.

Also, along the inner surface 174 i, end 174 defines a projecting ring180 that projects into receiving groove 50 of safety cartridge 1 andreceiving groove 140 of central cartridge support 130.

Also referring to FIG. 13A, it is noted that the access cover projection123 projects into receiving groove 177 of the primary cartridge 102.

In the next sections, some advantages from the various featurescharacterized herein above will be discussed. Before turning to those,it is noted that there are some example dimensions provided in FIGS. 13and 13A. As with other example dimensions herein, these are meant to beexample of dimensions are workable in a system, but alternatives arepossible.

The example dimensions are as follows: ZA=605.2 mm; ZB=179.5 mm;ZC=354.6 mm; ZD=27.2 mm; ZE=47 mm; ZF=23.6 mm; ZG=20.8 mm; ZH=2 mm;ZI=33.2 mm; ZJ=37.7 mm; and, ZK=44.42 mm.

B. Advantages Relating from Preferred Features Characterized HereinAbove1. Advantageous Safety Filter Cartridge Characteristics for Use with aTapering Main Filter Cartridge

Referring to FIG. 13, as indicated above, in a typical, preferred,application of features as characterized herein, the main filtercartridge 102 tapers in both outer perimeter 150 p and inner perimeter150 i definition, in extension from media end 151 to media end 152. Thismeans that the internal cross-dimension surrounded by media innerperimeter 150 i tapers downwardly along the same extension.

This can restrict the space available for safety 1, within interior 102i. As a result, in a typical application, the safety cartridge 1 isconfigured to project no further than a location of at least 90% of adistance between end 150 a and end 150 b of surrounding media 150,typically no greater than 85% of this distance and usually an amountwithin a range of 65-85% of this distance, in the direction of extensionfrom end 150 a toward end 1. This allows the tapering of inner perimeter102 i, to extend a definition quite narrow at end 150 b. Indeed, themedia 150, of the main cartridge 102, may in some instances, only clearend 8 of cartridge 1, by a radial dimension of 8 mm or less.

However, this means the safety cartridge 1 is of somewhat limitedlength, with respect to safety media 2. To avoid undesirablerestriction, the safety cartridge 1 is provided with pleated mediaadjacent end 4, to increase surface area available, and decrease facevelocity. This is an advantageous improvement, with a safety cartridgeused with a main cartridge that tapers downwardly, especially if themain cartridge tapers downwardly to a width too narrow to accommodate,conveniently, a substantially longer safety cartridge.

It can also now be understood how the relatively wide outer pleats 11 ofthe safety cartridge 1 adjacent end 4, can provide for advantageousflow. This is because the outer pleats 11 define spaces therebetween,along which the air can flow after it passes through the main filtercartridge 102 and as it is directed into the safety 1, to be directed tothe outlet 106. This too is advantageous for controlling restrictionincrease from the presence of the safety cartridge 1.

Referring to FIG. 13, to accommodate the relatively short safetycartridge 1, the main cartridge 102 includes a central projection 172that projects (a maximum amount in extension in a direction from end 152of the media toward end 151) at least 70 mm, typically at least 80 mmand often an amount within the range of 100-140 mm; and typically anamount of a distance between the ends 152,151 of at least 15%, typicallyat least 20% and sometimes an amount within the range of 24%-40% of thisdistance of extension.

2. Advantages from the Configuration of the Media Adjacent Media End 3

Advantages are also provided by the lack of pleats (or minimal pleatdepth) adjacent end 3 of the media 2 and safety 1 as discussed above.The advantages from this are that adjacent end 3, the media 2 andcartridge 1 take up relatively little radial dimension. Thus, theoverall cartridge 1 has relatively little radial dimension adjacent seal26 so it can fit into a narrow recess 150 r, FIG. 12A. This means theradial projection of the cartridge 1 around the air flow exit, does notcontribute, to an undesirable extent, to restriction to air flow to theoutlet 106, to advantage.

3. Advantages at the Interaction between the Safety Cartridge 1 andCentral Cartridge Support 130

The central cartridge support 130 provides support to the safetycartridge 1 ensuring proper orientation within the assembly 100. Aengagement of particular advantage between the safety cartridge 1 andthe central cartridge support 130 occurs in the region of centralprojection 139.

First, to advantage, an optional cushion engagement is provided betweenthe central projection 139 and the safety cartridge 1, by grommet 48 (48v) when grommet 48 (48 v) is resilient. This helps avoid a hard plasticto hard plastic engagement at this location. The cushioning effect isprovided by constructing grommet 48 (48 v) from an appropriatelycushioned or flexible, i.e. resilient, material as discussed previously.

Also, in the particular example depicted, the central projection 139extends completely through aperture 40 a in the safety cartridge 1. Whenthis is the case, it is desired to provide a seal closing aperture 40 a.The optional grommet 48 (48 v) also provides for this by comprising aresilient material that releaseably, sealingly, engages projection 139.

In the example depicted, the central projection 139 includes an optionalhead or tip 145, i.e. wider portion, and a narrow neck section orportion 146. This also is advantageous in combination with the optionalgrommet 48 (48 v). In particular, as the safety cartridge 1 is pushedover central cartridge support 120, eventually head or tip 145 willengage grommet 48 (48 v). It will push through, expanding the aperturein the grommet 48 (48 v). Eventually it will project outwardly from thegrommet 48 (48 v) providing an interference fit as shown in FIG. 12B, bythe tip 145, being wider than the aperture in the grommet 48 (48 v),when the grommet 48 (48 v) surrounds the neck section 146. Thisinterference fit will help keep the cartridge 1 in place on the centralcartridge support 130 as the main cartridge 102 is installed andremoved, and as servicing occurs when the cartridge 102 is removed. Theamount of interference is preferably not so much that it can't beovercome by a service provider pulling on the safety 1, but is alsopreferably adequate to help secure the safety in position againstundesired movement, and thus provides advantageous effect.

4. Advantages from Projection/Receiver Interaction Among the SafetyCartridge 1, the Central Cartridge Support 130, the Main Cartridge 102and the Access Cover 110

In the system 101 depicted, as discussed, the central cartridge support130 and the safety cartridge 1 are relatively short, by comparison tothe length of extension of the main cartridge 102, and for that matter,the housing 101 in extension along the central axis X (i.e. in an axialdirection). The interaction described among the safety cartridge 1 atend piece 20; the central cartridge support 130 and cartridge supportend 132; the main cartridge 102 at end piece 170 and in particularsection 172 at end 174; and, the access cover 110, especially inconnection with projection 123 and recess 124, provide for a number ofadvantages. For example, the main cartridge 102 and the safety cartridge1 are well stabilized in their respective positions. Also, they aresecured in a desired orientation for proper operation and easyinstallation and removal. Further, the interaction helps ensure that themain cartridge 102 and the safety 1, are proper ones for the system 101of interest, and cannot be improperly installed; i.e. installed withoutappropriate and proper sealing.

5. Advantages from the Optional Projection Arrangement 55 r, FIG. 1B

The optional projection 55 r, FIG. 1B, can also provide advantage. Inparticular, it can form a bumper against which a portion of maincartridge 102, can press if the safety 1 is not fully installed beforethe main cartridge 102 is installed. This will help push the safety 1into a proper sealing position over central cartridge support 130. Insome instances, it may be desirable to form projection 155 r from arelatively resilient material, so as to facilitate this type ofengagement. This can be done with a molding operation that provides aresilient material at region 155 r if desired.

6. Advantages from a Free End of the Media at Tip 3 t

As explained above, preferably the media 2 is provided with a tip 3 tthat is free, i.e. is not embedded in an end cap, and is not surroundedby any portion of cartridge support 29. This is advantageous, in that itprovides not only for a narrow width dimension of the cartridge 1 atthis region, for insertion in the recess 150 r, but it also leaves thetip 3 t free to provide for a secondary sealing effect within recess 150r and also some cleaning effect as it is removed during servicing of thecartridge 1.

IV. Some Selected Variations, FIGS. 14 and 15

In FIG. 14, a schematic cross-sectional view of a housing analogous tothe view of FIG. 11 is depicted. The depiction of FIG. 14 is meant toindicate an example of a usable variation. Like features would have alike operation.

Referring to FIG. 14, the housing 300 depicted includes a main housingpart 301 having an access cover 303 thereon. The main housing part 301may be generally analogous to part 109, FIG. 11. The access cover 302may be generally analogous to access cover 110, FIG. 11. The particularaccess cover 302 is varied somewhat in the region of projection 305 inthat central recess receiver 306 is deeper than receiver 124, FIG. 11A.Also, it is surrounded by a second projection 307. However, it can beused in general in a manner analogous to access cover 109, FIG. 11.

In FIG. 15, a cross-sectional view of an alternate cartridge 350 to maincartridge 102 is depicted. Like features have like operation. It isnoted that a closed end 351, a projection 352 is shown comprising aportion of a liner 353 that extends completely between opposite end caps354, 355. The projection 352 can operate similarly to projection 172,FIGS. 13 and 13A. It is also noted that projection 352 includes an endhaving a recess 360 analogous to recess 178 r, and outer surface 361with a projection 362 thereon surrounded by a recess 363. These featurescan operate analogously to analogously described and depicted featuresfor the embodiment of FIG. 13A. Also, spaced centering fins 370 areviewable on outer surface 352 o. They are directed toward central axis Xand projection 362. The centering fins 370 will fit around ring 307,FIG. 14. The fins 370 preferably surround a portion of projection 362.There are preferably 3-8 such fins 370.

In FIG. 15, example dimensions are indicated as follows: Q1=520 mm;Q2=392.5 mm; Q3=14.5 mm; Q4=239.3 mm; Q5=98.5 mm; Q6=4 mm; Q7=3 mm;Q8=269.6 mm; Q9=160 mm; and, Q10=135 mm. Of course, the arrangement canbe implemented with alternate dimensions.

V. Additional Example Arrangements; Components; Features; Techniques andMethods, FIGS. 16-57

In FIGS. 16-57, some additional examples of assemblies, components,features, techniques and methods usable in applications of the presenttechniques are shown and described. The features and componentscharacterized in this section demonstrate some variations that can bepracticed, to advantage; and, each can be implemented using various onesof the methods, systems, components, and techniques, previouslydescribed, There is no specific requirement that an assembly, component,feature, technique or method involve all of the detail characterizedherein, or be practiced to achieve all advantage possible, in order toobtain at least some benefit according to the present disclosure.

A. A First Additional Example Filter Assembly, FIGS. 16-47 1. TheOverall Assembly, FIGS. 16-20

The reference numeral 401, FIG. 16, generally references an air cleanerassembly including components according to an additional example of thepresent disclosure. The air cleaner assembly 401 generally comprises: ahousing 402; a main filter cartridge 403; and, a safety filter cartridge404. The housing 402 comprises a housing body section or body 402 a;and, a removable access cover 402 b that allows for access to aninterior 402 i of the housing 402, for example for service access to themain filter cartridge 403 and safety cartridge 404.

Still referring to FIG. 16, the housing 402 includes, positioned in thehousing body 402 a, a central support 407. The operation, function andexample structure of the support 407 are described in more detail below.In general, it provides the support function with respect to internallyreceived filter cartridges 403, 404, analogously to previously describedsuch supports herein.

Still referring to FIG. 16, the housing 402 includes a flow inlet (orinlet flow) arrangement 410 and a flow outlet (or outlet flow)arrangement 411. At 414, an optional cap is depicted, that can bepositioned over structure on outlet 411.

In a typical application, the assembly 401 would be an air cleanerassembly, for example, as used for an internal combustion on a vehicleor other equipment. Air to be filtered would enter the housing 402through flow inlet arrangement 410, would be passed, consecutively,through media of the main filter cartridge 403, and then through mediaof the safety cartridge 404 (if used). The filtered gas would then passin an outwardly direction from the housing through outlet arrangement411 to be directed to downstream equipment as appropriate for thesystem.

In FIG. 17, a side elevational view of assembly 401 is depicted.Features previously characterized include: housing 402, comprising bodysection 402 a and access cover 402 b; inlet arrangement 410, outletarrangement 411; and, optional cap 414.

In FIG. 18, the assembly 401 is depicted, in plan view directed towardaccess cover 402 b. The access cover 402 b is depicted with mountinglatches 417 thereon, to secure it to the housing body 402 a. Also,evacuator valve 418 is shown positioned over evacuator tube 419,allowing for water and/or some dust egress from interior 401 duringoperation.

In FIG. 19, the bottom plan view of the air cleaner assembly 401 isprovided. A mounting pad arrangement 420 is viewable, for securingassembly 401 to equipment in use. Mounting pad arrangement 420 can bemolded integral with a remainder of the housing body 402 a, or it can beseparately made and attached.

In FIG. 20, a plan view taken toward outlet 411 is provided.

2. The Main Filter Cartridge Generally, FIGS. 21-30

In FIGS. 21-30, general features of the main filter cartridge 403, FIG.16, and features of selected componentry thereof are shown. Referring toFIG. 21, a perspective view of main filter cartridge 403 is depicted.The main filter cartridge 403 comprises a media pack 431 positionedsurrounding an interior volume. The media pack 431 extends between firstand second opposite end pieces 432, 433 (and comprises media 431 mextending between media ends 431 a, 431 b). For the example depicted,end piece 432 is an open end piece having an open central aperturetherethrough for flow of material between the exterior region and aregion surrounded by the media pack 431. For the example depicted, endpiece 433 is closed, and is configured with selected features toadvantage discussed further below.

The media pack 431 can comprise a variety of materials. It may includean inner liner, an outer liner, or both. Typically, it will include atleast an inner liner as discussed below.

A variety of materials can be used for the media 431 m of media pack 431generally as intended or desired for the application of use. Typically,the media 431 m will comprise pleated media but alternatives arepossible.

The particular media pack 431 depicted generally has a circularcross-section, although alternatives, such as oval, can be applied insome arrangements according to the present disclosure. The particularmedia pack 431 depicted also tapers downwardly in shape orcross-dimension, in extension from adjacent the open end since 432 toadjacent the closed end piece 433. While this if typical, preferred andadvantageous, alternatives are possible with application of some ofprinciples described herein.

Still referring to FIG. 21, the particular cartridge 403 depicted,includes, surrounding the media pack 431 and media 431 m thereof,adjacent the closed end 433, an optional dust ejector outlet shield ormargin arrangement 435. This margin arrangement 435 provides an optionalimpermeable shield around the media 431 m at a location that overlapsthe housing evacuator tube 419, FIG. 16.

In FIG. 22, a plan view taken toward end piece 432 is viewable. Aninterior 403 i of the cartridge 403 is viewable, through to adjacent endpiece 433.

Referring now to FIG. 23, a side elevational view, with a portion shownin cross-section, of the cartridge 403 is provided. Selected features ofend piece 432 can be seen in cross-section. For example, a central flowaperture 438 can be seen, providing communicating flow with interior 403i of the cartridge 403, surrounded by the media pack 431. Portions of aninner liner 439 discussed further below can be seen. Also, a housingseal arrangement 440 on end piece 432 can be seen. The particularhousing seal arrangement 440 depicted, comprises a radially directedhousing seal member 441. In this instance, the radially directed housingseal member 441 is configured as a radially inwardly directed housingseal arrangement 441 i; i.e. it is directed toward axis X. As will beseen, as a radially inwardly directed arrangement it is configured toform a releasable housing seal between the cartridge and a portion 402when pushed thereover.

Also, still referring to FIG. 23, selected external features of the endpiece 432 can be seen. In particular, attention is directed to optionalcushion or bumper arrangement 443 and to optional groove 444. The bumperarrangement 443 is configured to be pressed against a housing and wallsection or housing portion axially, when the cartridge 403 is installed,to help cushion and stabilize the cartridge 403 in position. The grove444 can be a remnant from a mold stand-off ring during molding of theend piece 432. It can also be oriented and used as a receiver ring, toreceive a portion of housing projecting therein, when the cartridge 403is installed. The groove 444, when used, will typically be continuous,in extension around a central axis X, but alternatives are possible. Theend piece 432 will typically be molded-in-place from material such as afoamed polyurethane having a hardness, Shore A, of the typecharacterized previously herein. Alternatives, of course, are possible.

Groove 445, positioned radially outwardly from liner 439 and radiallyinwardly from groove 444, is an optional groove. It can be an artifactfrom certain types of molding operations, but can be left off if desiredin some instances.

In FIG. 24, a cross-sectional view of the filter cartridge 403 isprovided. In FIG. 24, the liner 439 can be seen in greater detail,extending between opposite ends 432 x, 433 x (where the end pieces 432,433, respectively are positioned). The liner 439 can thus be seen ashaving opposite ends 439 a, 439 b, with sidewall structure 439 sextending therebetween. For the example depicted, the sidewall structure439 s is a lattice structure of longitudinal (axial) supports 439 t andcircumferential ribs 439 r, to provide a porous structure that alsosupports media 431 m of media pack 431 along an interior 431 i thereof.

For the particular example arrangement depicted, the sidewall 439 s istapering, because it is configured to support a tapering media pack 431(and media 431 m) in extension between the end pieces 432, 433.Typically, an angle of taper along outer pleat tips, or media surface,and will be at least 0.3°, usually at least 0.5°, typically not morethan 5°, and often within the range of 0.3-3°, inclusive, althoughalternatives are possible. The angle of taper reference is meant to bean angle relative to central axis X.

Still referring to FIG. 24, support end 439 a is shown positionedembedded in and adjacent end piece 432. It is generally an open end,allowing for positioning around, and in supporting relation to, housingseal arrangement 441.

Still referring to FIG. 24, end 439 b, on the other hand, surrounds aclosed central end structure 439 e positioned on liner 439 and closing acentral region across the media interior 431 i. Selected features of theclosed end structure 439 e are discussed herein, in connection withother figures. In general terms, the closed “central end structure” asthe term is used in this context, is structure which extends across, andcloses, an interior 431 i of the cartridge 403 at a location remote fromliner open end 438 (i.e. remote from cartridge end piece 432).

In FIG. 25, a schematic exploded view of the cartridge 403 is depicted.Components discussed are characterized by like reference numerals. It isnoted that the exploded view of FIG. 25 is schematic, and the partswould not typically be separable in the manner shown. For example,typically the portions of the end pieces 432, 433 shown at opposite endsof the figure, would be molded-in-place on media 431 m and would not beseparable therefrom.

Attention is now directed to FIG. 26. FIG. 26 is an enlargedcross-sectional view of the liner 439. Referring to FIG. 26, adjacentend 439 a is provided an end ring 450 with a plurality of flow apertures451 therethrough. During molding of end piece 432, resin can flowthrough the apertures 451, facilitating connection between themolded-in-place portion of the end piece 432 and the liner 439 whilealso ensuring the structural back-up support to the seal 441 r. Spacedprojections 452 can be housed as mold stand offs.

FIG. 27 is an end view taken generally toward end 439 a. FIG. 28 is anend view taken generally toward end 439 b.

In FIG. 29, a perspective view of liner 439 is provided. Apertures 439 qallow for resin flow, during molding of molded-in-place portions of endpiece 433, FIG. 25.

In FIG. 30, an enlarged fragmentary cross-sectional view is taken of aportion of FIG. 26, i.e. of liner 439, in particular in the region ofclosed end 439 e. The closed end 439 e can be seen as defining, in aresulting cartridge 403, FIG. 21, a closed central region 460 extendingacross a cartridge interior 403 i. Referring again to FIG. 30, centralregion 460 has an inner surface 460 i and an opposite outer surface 460x. The inner surface 460 i is the surface that faces interior 403 i of aresulting cartridge 403, FIG. 21, i.e. faces toward the end piece 432.Surface 460 x is an outer exterior surface, and faces away from interior403 i and generally away from end piece 432.

Some selected features of the liner 439 and the resulting filtercartridge 403, viewable in FIG. 30, include the following. Along aninterior 460 i, the end member 460 includes a projection 462 thatprojects toward interior 403 i and the opposite end 432 of the resultingcartridge 403. Further, the projection 462 surrounds a receiver recess463 that projects away from interior 403 i and the opposite end 432, inthe resulting cartridge. The receiver recess 463 is closed by centralportion 460 p of the closed end 460.

For the particular assembly depicted, the projection 462 is a continuouscentral ring surrounding (and in the example centered on) central axisX. The ring 462 is defined by spaced outer and inner walls 464, 465,joined at end ring 466.

An outer surface 460 x, the two sidewalls 464, 465 and end portion 466define a receiving groove 470 surrounding a central projection 471, anend of which is defined by central projection 460 p. The groove 470, itwill be understood, is sized, positioned and located to receiveprojecting therein, a portion of an on the access cover, discussedbelow. Further, the projection 471 is sized to project into centralreceiver on an access cover surrounded by a portion that projects intogroove 470 in the access cover. It can be seen that, for the example,inner sidewall 465 is a sidewall portion of the projection 471.

3. General Features of the Housing 402 and Body Section 402 a, FIGS.31-36

In FIG. 31, an exploded perspective view of certain features of thehousing body section 402 a is depicted. Referring to FIG. 31, it can beseen that the housing body section 402 a includes a sidewall 480 withinlet 410 therein, and an end wall or region 402 x with outlet 411therein. Mounting pad or foot pad arrangement 420 is shown positioned onthe sidewall 480 at appropriate locations for mounting of the bodysection 402 a and indeed the overall assembly 401, FIG. 16, as desiredfor use. Again, regions 420 can be molded-in-place or they can bepreformed and then be secured in place.

Referring in general to FIG. 31, additional, internal, structure isdepicted. In particular, central support 407, if depicted which, for theexample shown can be preformed and then be secured, or positioned, inhousing section 402 a. Another feature is optional and preferred rampmember 485, which can be preformed and then be secured within endsection 402 a.

In general, the support 407 can provide, in use, for desired support tointernally positioned structure such as one or both of filter cartridges403, 404. This is discussed further below. The ramp 485 can be preformedand then secured within the assembly, appropriate so that air enteringinlet 410 is directed into a cyclonic pattern.

In FIGS. 32-36, the support 407 is depicted in greater detail.

Referring to FIG. 32, support 407 is shown in perspective. The support407 comprises first and second ends 490, 491, with side or sidewallstructure 492 extending therebetween. For the particular exampledepicted, the side structure 492 is a lattice structure, allowing forflow of material being filtered, for example, air, therethrough in use.Operation with respect to this is discussed further below.

End member 490 generally surrounds an open end 490 x allowing for fluidflow communication with an interior region surrounded by lattice 492.End 491 is typically configured with features for interacting withsupport components such as a safety element and/or main filter elementas discussed below.

End 491 is a support end, and includes a number of preferred features.For example, it includes radially outwardly projecting, spaced,projection sections 491 r that become positioned between projections onan end of the safety or secondary filter cartridge in use. End 491 alsoincludes central projection 490 or receiver recess 504 and centralprojection 506.

In FIG. 33, a cross-sectional view of central support 407 is provided.At end 490, around aperture 490 x, a plurality of spaced, flexiblemembers 490 p are provided. These are configured to engage, in asnap-fit manner, structure in or at housing end 402 x, FIG. 31, duringinstallation. Often, a hook or ratchet engagement is used, in a typicalapplication, so that once the support 407 is positioned within thehousing 402, it is not readily removable. This does not mean that itmust be configured to never be removable, only that it typically wouldnot be desired to have it removed. It is noted that in some instances,the support 407 can be configured to be integral with a remainder of thehousing 402, but in typical preferred applications, it will be aseparately made piece that is pushed in place during assembly.

In FIG. 35, and end view taken toward end 491 is provided. In FIG. 36,and end view taken toward end 490 is provided.

In FIG. 34, an enlarged fragmentary cross-sectional view of anidentified portion of FIG. 33 is shown. Here, some selected features ofthe support 407 can be viewed.

Referring to FIG. 34, end 491, which can be viewed as a cartridgeengagement end of support 407, includes a central projection 493 thatprojects, generally, in a direction away from end 490, FIG. 33, and thusin use toward the access cover 402 b. Projection 493 is surrounded byrecess or receiving groove 494. Projection 493 extends, in the exampledepicted, to a tip 495 positioned on a narrow neck 496; the tip 495having a slightly larger cross-dimension then the net 496. Operation ofthe tip 495 and neck 496 during engagement with cartridge structure, isdiscussed further below.

4. Features of the Example Safety Filter 404, FIGS. 37-45

In FIGS. 37-45, safety filter 404 and its components are depicted.Referring to FIG. 37, safety or secondary filter 404 is depicted in anexploded view as comprising: safety cartridge section 404 a, seal ring501, and cushion member or grommet 502.

In general, the safety filter region 404 a comprises a media pack 404 mextending between opposite ends 404 a, 404 b. It may be generally aspreviously described herein for FIGS. 1-15.

A depicted grommet or cushion member 502 differs in detail frompreviously described such grommets or cushion member, but generally ispositionable within an aperture 505 on a central projection 506positioned in end 404 b. The grommet or cushion member 502 can be formedand then pushed into the aperture 505; or, it can be preformed and putinto a mold of when end 404 b is molded. It would typically be preformedand then be pushed into a preformed projection 506 and aperture 505. Itwill be typically be formed from a resilient thermoplastic elastomersuch as a silicone rubber or similar material, with a hardness ascharacterized for a similar part previously herein, as its function isgreatly operated as a cushion member as discussed below. Still referringto FIG. 37, the seal ring 501 is an o-ring positionable within receivinggroove 404 g. Alternately, the seal 501 can be a molded-in-place sealmember.

In FIG. 38, cartridge 404 is depicted in side view, with selectedportions shown broken away and in cross-section. Referring to FIG. 38,cartridge 404 can be seen as comprising media extending between ends 404a, 404 b. Except as detailed below with respect to grommet 502, ingeneral, the cartridge 404 can be analogous to similar cartridgesdiscussed previously, including with respect to alternatives andvariations thereof characterized previously.

In FIG. 39, a plan view taken toward end 404 b is viewable. Cushionmember or grommet 202 can be viewed.

In FIG. 40, an enlarged fragmentary cross-sectional view of anidentified portion of FIG. 38 is shown. Here central projection 506 canbe viewed: as being surrounded by groove or receiver 504; and, as havinga tip 506 t, remote from end 404 a, FIG. 37. The tip 506 t surroundsdefines an aperture 505. Cushion member or grommet 502 is positioned inthe aperture 507.

More specifically, cushion member or grommet 502 extends through theaperture 505, and in the example depicted, fully closes it. Cushionmember or grommet 502 includes and defines an interior receiver region508. Receiver region 508 is positioned at least partly surrounded byprojection 506. The particular region 508 depicted, narrows to a neck509 and an end portion 510 positioned along axis X on an opposite sideof neck 509 from end 404 a, FIG. 38. The interior 502 i of the cushionmember or grommet 502 is defined to receive snuggly therein (andpreferably in an interference manner) a portion of projection 493, FIG.34 on central support 407. In particular, tip 495 would be receivedwithin region 510 and narrowed neck 496 would be engaged by neck 509, ina manner analogous to providing described cushion members.

In the example of FIG. 40, however, it is noted that region 510 isclosed by an end section 502 x of cushion member 505 positionedexteriorly of projection 506 and beyond tip 506 t.

Still referring to FIG. 40, cushion member or grommet 502 includesthereon, an engagement arrangement 511. It is sized to project acrosstip 506 t to terminate at an outer region 511 o positioned extendingradially outwardly from axis X beyond projection 506 at tip 506 t.Preferably it extends at least 0.5 mm, usually at least 1 mm radiallybeyond tip 506 t. In a typical arrangement, outer region 511 a iscircular, as can be seen in FIG. 39. However, alternatives are possible.Region 511 o is configured to engage a filter cartridge in a preferredmanner, as discussed below.

In FIG. 41, cushion member or grommet 505 is viewable in perspectiveview.

In FIG. 41, gusset 502 g can be seen supporting outer region 511 o.

In FIG. 42, an enlarged cross-sectional view of member 505 is viewable.

In FIG. 43, an end view of member 502, taken toward the interior and end508, FIG. 40 is provided.

In FIG. 44, a side elevational view of cartridge 404, minus seal ring501, FIG. 37, is provided. The media 404 m can be pleated mediaanalogous to that described previously for the arrangements of FIGS.1-15. Thus, it may have outer pleat tips and inner pleat tips withdifferent angles of extension relative to central axis X.

FIG. 45, a partial cross-sectional view taken of cartridge 404, inaccord with line 45-45, FIG. 44 is provided. Only a portion is shownbroken away an in cross-section. In FIG. 45A, an enlarged fragmentaryview of that portion is shown, and one can see outer support rib 473 rextending along a tip 474, of a media pleat 475.

5. Selected Features of the Component in Interaction, FIGS. 46-47

In FIGS. 46 and 47, selected features of interaction among componentsfor air cleaner 401, FIGS. 16-20, are shown.

In FIG. 46, an enlarged fragmentary schematic cross-sectional view takenadjacent access cover 402 b is shown. Referring to FIG. 46, the accesscover 402 b can be viewed as having an end or interior surface 520 witha central housing or access cover projection 521 thereon, projecting ina direction from end surface 520 toward: interiorly received cartridges403, 404; support 407; and, housing base 402 a, not shown.

The central projection 521 surrounds and defines a central receiverrecess 522. For the particular example depicted, the projection 521 iscentered on and surrounds central axis X. This will be typical, but isnot necessarily required in all instances.

Still referring to FIG. 47, central access cover projection 521 can beseen as projecting into and being received by, groove 470 on end 439 e(460) of cartridge 403; and, to project to a location between inner andouter walls 465 and 464 respectively. As a result, cartridge projection471 is shown depicted extending into access cover recess 522.

In FIG. 46, projecting ring 462 on an interior surface of end piece 439e (460) of the main filter cartridge 403 can be seen projecting into agroove or recess 504 on the safety cartridge 404, surrounding centralprojection 506, and positioned between projection 506 and outer sidewall504 s of the remainder or groove 504.

Attention is directed to cushion member or grommet 502. The outerportion 511 o can be seen engaging, a radially interior surface portionof projection 471 on main cartridge 403. This would be a cushion memberarrangement portion.

Still referring to FIG. 46, attention is directed to projection 493 onthe support 407. It can be seen as having tip 495, projecting into thecushion member or grommet 502 as described above.

It can be seen from FIG. 46, that a cushion interaction is provided,among selected components, namely: grommet 502 and main cartridge 403,in projection 471; and, between support 407 and grommet 502 at tip 495.This can help provide for secure engagement, and a cushion one that doesnot tend to allow rubbing between adjacent parts in a manner that cancause damage to one or the other or both.

In FIG. 47, an enlarged fragmentary view showing interaction in a regionat an opposite end of the assembly from region 46 is shown. Here, outlet411 is shown reinforced by support ring 530. Also, seal flange 531 isviewable, for engagement by seal member 501 on the safety filter 404,along an inside of flange 521; and, by seal member 440 on the mainfilter cartridge 403 at an outside. Further, the flange 531 can be seenas defining a groove 533, between the flange 531 and the support 407, ofan end of the safety 404 therein. A tail 534 of the safety media can beseen projecting down into this groove 533.

Still referring to FIG. 47, projection 536 on an end of the housing body402 a can be seen projecting into groove 444 on the main filtercartridge 403.

6. Example Dimensions for the Arrangement of FIGS. 16-47

Selected ones of FIGS. 16-47, some example dimensions for thearrangement depicted are provided. Although variations from thedimensions can be practiced, the following list of example dimensions,will facilitate application of the practice of the invention, whether inthe particular size depicted or alternate sizes.

In FIGS. 16-47, the example dimensions indicated can be for example asfollows: TA1=350 mm; TA2=274.8 mm; TA3=331.9 mm; TA4=227.8 mm; TA5=125.8mm; TA6=350.5 mm; TA7=210.4 mm; TA8=126.8 mm; TA9=337.5 mm; TA10=6 mm;TA11=85.3 mm; TA12=210.4 mm; TA13=148.6 mm; TA14=141.8 mm; TA15=337.5mm; TA16=12 mm; TA17 is meant to indicate a wall thickness in the regionidentified as 2.5 mm; TA18=33 mm; TA19=4.5 mm; TA20=4 mm; TA21=34.4 mm;TA22=25.2 mm; TA23=127.5 mm; TA24=14.5 mm; TA25=8.5 mm; TA26=4 mm;TA28=2.9 mm; and, TA29=25 mm; TA30=95.2 mm; TA31=295.9 mm; TA32=28.3 mm;TA33=23 mm; TA34=50.5 mm; TA35=11.1 mm; TA36=5.6 mm; TA37=4.9 mm;TA38=25.6 mm; TA39=6.6 mm; TA40=2.1 mm; TA41=4.4 mm; TA42=126.1 mm;TA43=297.5 mm; TA44=14.6 mm; TA45=5 mm; TA46=15 mm; TA47=4.9 mm; TA48=5mm; TA49=20.3 mm; TA50=73.2 mm; TA51=69.3 mm; TA52=69.3 mm; TA53=5 mm;TA54=5 mm; TA55=23.1 mm; TA56=47.8 mm; TA57=33.5 mm; TA58=27.5 mm;TA59=27.5 mm; TA60=38.1 mm; TA61=51.4 mm.

Referring again to FIG. 46, preferably the tip or ring 462, where theinner wall 465 and outer wall 464, defining the receiving groove in theouter surface of the end piece 439 e, has a width dimension of nogreater than 20 mm, typically no greater than 30 mm, preferably nogreater than 25 mm, and usually within the range of 5-16 mm. Althoughalternatives are possible. Typically, the outer wall 464 has an innersurface portion facing axis X that extends fairly steeply, preferably atan angle of at least 85°, typically at least 86°, and usually within therange of 87-89.5°, relative to a plane perpendicular to the central axisX.

Although alternatives are possible, typically and preferably, aninterior surface of projection 471 at a location where engaged bycushion member 511 o, is circular in cross-section, and is engaged bythe outer perimeter of member 411 o in a 360° arc around the centralaxis X. Typically, this surface portion has a cross-dimension slightlysmaller than a cross-dimension of the cushion member at this location,preferably at least 0.2 mm smaller, usually at least 0.5 mm smallersometimes 1 mm or more smaller. Typically, the overall dimension of theengagement portion 511 o of the cushion member 510 has a cross-dimensionof at least 12 mm, typically at least 15 mm, usually not more than 26mm, and typically not more than 23 mm. Typically, surface portion 565,where engaged by the cushion member 511 o, extends at an angle, relativeto a plane perpendicular to central axis X, of at least 84°, typicallyat least 85°, often within the range of 86°-89.5°. Alternately stated,typically that surface portion extends at an angle relative to centralcartridge axis X of at least 0.5°, typically no greater than 6°, andusually within the range of 0.5-4°.

With respect to the definition of regions where a surface of wall 465,i.e. an inner surface of projection 471, engages cushion arrangement502, and in particular perimeter 511 o, is not meant to be suggestedthat no portion of the projection 471 varies from the definition given.Rather, the intent is meant to refer to the portion engaged when thecartridge is fully engaged with a grommet member 502, duringinstallation.

Typically, the groove 470 has a depth, in extension inwardly fromadjacent the outer wall 464, of at least 10 mm, typically at least 12mm, and often at least 14 mm, for example 14-30 mm.

B. A Second Additional Alternate Air Cleaner Assembly Example, FIGS.48-52

In FIGS. 48-52, a second additional embodiment using many of thefeatures of the arrangement of FIGS. 16-47, is depicted. A third isdepicted is FIGS. 53-57, as discussed in the next section. From thesefigures, additional variations and practices according to the presentdisclosure can be understood.

In previously described embodiments, safety or secondary filterconfigurations were described: that had an end remote from a seal end;and, that comprised a plurality of radially projecting members thatwould close ends of pleats; the members having recesses or spacestherebetween. This correlated with a preferred media definition that hadouter pleat tips and inner pleat tips that would were not the same, inangle of extension.

Advantages can be obtained from applications of certain featuresdescribed herein, even when the safety secondary filter configuration ismore conventional with respect to the media pack; for example, a safetyfilter media pack comprises a cylindrical shape or slightly conicalshape without tapering pleat ends. This is among the variations thatwill be understood from the embodiments of FIGS. 48-57.

In FIG. 48, an example air cleaner assembly 601 is depicted comprisinghousing 602. The housing 602 comprises a housing body 602 a with aremovable access cover 602 b positioned thereon via latches 617. Theaccess cover 602 b includes a evacuator tube 619 with evacuator valvemember 618 thereon. The housing 602 further includes inlet 610 andoutlet 611. Mounting pad arrangement 620 is shown positioned on thehousing body 602. Here, the mounting pad arrangement 620 is configuredso that the assembly 601 is suspended from an equipment section in use,but alternatives are possible.

In FIG. 49, an exploded perspective view of air cleaner assembly 601 isprovided. The assembly 601 includes: housing 602; main filter cartridge603; safety cartridge 604; and, positioned in the housing body 602 a,support 607. Also viewable is cap 614. Except for variation in thesupport 607 and safety 604, discussed herein below, the parts can begenerally analogous to ones previously described herein.

In FIG. 50, a cross-sectional view of air cleaner assembly 601 isprovided. A depicted main filter cartridge 603 can be seen as comprisingmedia pack 631 (comprising media 631 m) extending between ends 631 a and631 b, and end pieces 632 and 633. The media pack 631 is seen asincluding inner liner 639 around which the media 631 m is positioned.End piece 632 is generally configured analogously to end piece 432, andforms an internally directed radial seal by seal member 640; which ispositioned to seal around a seal flange 643 in housing 602. End piece633 operates generally analogously to end piece 433 except for specificdetail referenced below.

Safety element 604 comprises media 605 around open interior 605 i,supported between ends 604 a and 604 b. End 604 a includes a radially(in the example outwardly) directed seal member 604 r thereon. In thisinstance, the depicted seal member 604 r does not comprise an o-ring,but an o-ring could be used. Rather, end piece 643 x, positioned in thesafety 604, would typically be formed from a material (such as a foamedpolyurethane) sufficiently soft and compressible to form an outwardlydirected radial seal in use.

It is noted that the safety 604 depicted, does not have a mediaconfiguration analogous to safety filter, discussed previously. Rather,safety 604 has a generally cylindrical media configuration, with media605 that does not change with respect to depth (for example, if pleated,pleat depth) throughout its length. Further, it will be understood thatat end 604 b, it is closed by an end piece having a generally circularouter diameter, rather than one having a space projection arrangementfor the safety 404. This is discussed further below.

Central support 607 is shown with an optional snap-fit in the housing atend 607 a. As can be understood from FIG. 49, support 607 is differentin specific configuration from support 407 previously discussed,although it is configured to provide an many analogous functions. Inparticular, while it comprises longitudinal extension 6071 and rib 607 rconstruction, at end 607 e, it is generally circular, and does not havea shape analogous to support 407 with alternating projections andrecesses as depicted in FIG. 32.

In FIG. 51, an enlarged fragmentary cross-sectional view of a portion ofFIG. 50 is shown, the portion being where engagement among the accesscover 602 b, main filter cartridge 603, safety or secondary cartridge604 and central (tower) support 607 occurs. The main filter cartridge804 can be seen as having closure member 639 e, across an interiorthereof, somewhat analogous to end 439 on liner 439. In the arrangementof FIG. 51, the closure member 639 e also comprises an end of a liner639 around which the media 631 m of cartridge 603 is positioned. Theclosure member 639 e includes an outer surface 639 x and an innersurface 639 i. Along the inner surface, a central receiver recess 663 isdefined ending in end or tip 660 p. Receiver recess 663 is defined byprojection 671 on an exterior surface 639 x. Surrounding the projection671 on exterior surface 639 x is a groove 670 positioned between innerand outer sidewalls 665 and 664 respectively, which join at end, ring orprojection, 662.

The safety or secondary filter 604 includes an end 701 extendingthereacross, closing an end 604 of the safety filter 604 at an endremote from seal 604 r, FIG. 50. The end 701 defines a centralprojection 706 having a tip 706 t which is open, with certain membergrommet 702 positioned therein. The grommet or cushion member 702 may begenerally analogous to grommet or cushion member 502, previouslydiscussed. Surrounding the projection 706 is a groove 707 definedbetween radially inner and outer walls 708 and 709; the inner wall 708comprising a portion of projection 706. Into this groove 707 between thewalls 708 and 709, projects projection ring 662 of the end piece 639 eon the main cartridge 603.

The support 607 includes an end 710 with a central projection 711thereon; the central projection 711 being surrounded by groove 713; and,having a tip 711 t and a narrow neck 711 n analogously to a previouslydescribed arrangement.

Further, access cover 602 b includes a central projection 715surrounding receiver 716. The receiver 716 is sized to receive extendingtherein, projection 663, projection 706, and projection 711. Theprojection 715 on the access cover, is sized to project into receivergroove 664 g on the main filter cartridge 403, between walls 664, 665.

In FIG. 51, an analogous interaction among the components to that shownin FIG. 46 and discussed above are provided. The grommet or cushionmember 702 is sized to engage, in an interference fit manner, aninterior surface of projection 663 along a sidewall section thereof, tostabilize the main filter cartridge. Further, grommet or cushion member702 is sized to engage the projection 711 adjacent tip 711 t, ininterference, cushion manner. This will help control movement of themain and safety filter cartridges once installed.

Also, various interactions among the grooves and projection depictedhelps ensure that only the proper cartridge are installed.

Still referring to FIG. 51, it is noted that aperture 716 in end portion710 of support 607 is viewable. On or more such apertures 716 can beused to receive one or more projections on a mechanical assembly forpositioning the support 607 in housing 602 during initial assembly.

In FIG. 48, example dimensions are as follows: TA62=302.8 mm; TA63=530mm; TA64=607 mm. In FIG. 51, example dimensions are indicated asfollows: TA65=22.8 mm; TA66=61.1 mm; TA67=53 mm; TA68=46.9 mm; TA69=38.9mm; TA70=52.9 mm; and, TA71=61 mm.

In FIG. 52, an enlarged fragmentary cross-sectional view taken throughthe assembly adjacent the outlet 611 is shown. The outlet 611 can beseen as having a reinforcing ring 611 r therein. Viewable in FIG. 52 areinwardly directed radial seal 640 on the main filter cartridge 603engaging seal flange 643. Also, safety cartridge 604 can be seenengaging flange 643 with an outwardly directed radial sealing member butnot using an o-ring, but rather using an end piece 643 a molded from anappropriately compressible material to provide the desired engagement.In the alternative, an o-ring engagement can be used.

Support 607 including long axial extensions 6071 and radial ribs 607 ris depicted. Inlet 610 can be viewed. As with other inlet arrangementsdescribed herein, inlet 610 can also be provided with a reinforcing ringanalogous to reinforcing ring 611 r and outlet 611, if desired.

The embodiment of FIGS. 48-52 shows that a cushion engagement among amain filter cartridge and support; and/or, among a safety filtercartridge and support, can be accomplished using a grommet arrangementanalogous to those previously described, except in a context of anarrangement with a softy element that does not use the various featuresor safety elements described in previous embodiments.

Referring again to FIG. 51, there are some preferred features anddimensions for the arrangements depicted. For example, typically andpreferably a tip of groove 664 g, extending between the walls 664, 665has a width of no greater than 30 mm, usually no greater than 28 mm,typically no greater than 25 mm. Also, preferably, sidewall 664, theouter sidewall of the groove 664 g extends or tapers outwardly at anacute angle relative to a plane perpendicular to central axis X of atleast 40°, typically at least 50°, often at least 60°, and usuallywithin the range of 60°-80°, inclusive.

Typically and preferably, an interior surface portion of projection 663,surrounded by and engaging the cushion arrangement 702, extends at anangle (taper angle) relative to the central axis X of at least 0.5°,typically at least 1°, and often within the range of 1-7°. Typically, itengages the cushion arrangement 702 along a 360°, continuousinteraction, with an interference. Typically, the dimension across theprojection 663 at this location is at least 0.2 mm smaller than anextension across a cushion member 702 where engagement occurs,preferably at least 0.5 mm smaller and sometimes 1 mm or more smaller.

Typically, the cross-dimension of projection 663 when the engagementoccurs, is at least 12 mm, typically at least 15 mm, and is preferablynot more than 26 mm, usually no more than 23 mm.

C. A Third Additional Example Embodiment, FIGS. 53-57

In FIGS. 53-57, an assembly generally analogous to the assembly of FIGS.48-52 is depicted. The assembly of FIGS. 53-57 is intended to beanalogous in structure and operation, except for dimension andstructural features that are included to accommodate that variation indimension. This will be understood from comments below.

In FIG. 53, an example air cleaner assembly 801 is depicted comprisinghousing 802. The housing 802 comprises a housing body 802 a with aremovable access cover 802 b positioned thereon via latches 817. Theaccess cover 802 b includes a evacuator tube 819 with evacuator valvemember 818 thereon. The housing 802 further includes inlet 810 andoutlet 811. Mounting pad arrangement 820 is shown positioned on thehousing body 802.

In FIG. 54, an exploded perspective view of air cleaner assembly 801 isprovided. The assembly 801 includes: housing 802; main filter cartridge803; safety cartridge 804; and, positioned in the housing body 802 a,support 807. Also viewable is cap 814. These parts can be generallyanalogous to those previously described for the embodiment of FIGS.48-52. The main cartridge 303, as with cartridge 603, can be analogousto cartridge 403.

In FIG. 55, a cross-sectional view of air cleaner assembly 801 isprovided. A depicted main filter cartridge 803 can be seen as comprisingmedia pack 831 comprising media 831 m extending between ends 831 a and831 b, and end pieces 832 and 833. The media pack 831 is seen asincluding liner 839 around which the media 831 m is positioned. Endpiece 832 is generally configured analogously to end piece 432, andforms an internally directed radial seal by seal member 840, beingpositioned to seal around a seal flange 843 in housing 802. End piece833 operates generally analogously to end piece 433 except for specificdetail referenced below.

Safety or secondary filter cartridge 804 is analogous to cartridge 604and comprises media 805 around open interior 805 i, supported betweenends 804 a and 804 b. End 804 a includes a radially (in the exampleoutwardly) directed seal member 804 r thereon. As with cartridge 604, aseal member 804 r does not involve an o-ring, but an o-ring could beused. Rather, end piece 843 x, positioned on the safety cartridge 804,would typically be formed from a material sufficiently soft andcompressible to form an outwardly directed radial seal in use.

Analogous to cartridge 604, safety cartridge 404 has a generallycylindrical configuration, with media 805 that does not change withrespect to depth (for example, if pleated pleat depth) throughout itslength. Further, it will be understood that at end 804 b, it is closedby an end piece 804 e having a generally circular outer diameter, ratherthan one having a space projection arrangement for the safety 404.

Support 807 is shown snap-fit in position at end 807 a.

As can be understood from FIG. 55, support 807 is analogous in specificconfiguration to support 607 previously discussed. It compriseslongitudinal extensions 8071 and ribs 807 r, end 804 e, it is generallycircular, and does not have a shape analogous to support 407 withalternating projections and recesses as depicted in FIG. 32.

In FIG. 56, an enlarged fragmentary cross-sectional view of a portion ofFIG. 55 is shown, the portion being where analogous engagement among (tothat described for FIG. 51) the access cover 802 b, main filtercartridge 803, safety cartridge 804 and tower support 807 occurs.

In FIG. 56, example dimensions are as follows: TA72=22.8 mm; TA73=48.1mm; TA74=423 mm; TA75=36.3 mm; TA76=47 mm; and, TA77=52.9 mm.

In FIG. 57, an enlarged fragmentary cross-sectional view taken throughthe assembly adjacent the outlet 811 is shown. The outlet 811 can beseen as having a reinforcing ring 811 r therein.

In FIG. 57, interaction among: the main filter cartridge 803; the safetyfilter cartridge 804; the support 807; and, the housing base 802 b isshown; the interaction being generally analogous to that discussedabove, with respect to the description of FIG. 52, and shown therein.

By a review of the features and indicated dimensions of FIG. 56 andcomparison to FIG. 51, still further alternate applications of thetechniques described can be understood. It is noted that analogousfeatures and appearance have analogous function.

VI. General Observations; Variations; and, Selectively DiscussedAdvantageous Features

A. Features Relating to Applicability with Variations in Safety Filteror Cartridge Type

From the above, it can be understood that techniques described hereincan be applied with variations in the type of cartridge. In FIGS. 1-47,filter assemblies and filter cartridge types can be described, in whicha secondary safety filter, positioned underneath a main filtercartridge, has a particular preferred media configuration in which themedia pleats terminate at an end piece remote from a seal end of thecartridge, which end piece comprises a central projection and aplurality of radially outwardly extending, spaced, projections withrecesses therebetween. The projections close ends of the pleats. Thearrangement is particularly well configured for use with mediaconfigurations in which pleat depth differs along a length from a firstend to a second length end, typically increasing in depth toward thesecond end, when the second end is remote from a mounting seal orhousing seal arrangement. The techniques can be applied when an endremote from the closed end piece having a central projection is notpleated at all, or is only pleated a small amount. The techniques can beapplied when the seal is an o-ring, however alternatives are possible.The technique can be applied when an end of the media adjacent seallocation is a free end, although alternatives are possible.

As shown and described in connection with FIGS. 1-47, a support can bepositioned within the housing, along an interior of the safety cartridgewhen the safety cartridge is installed, that is configured to engagewith and support the media in a desired manner. Further, safetycartridge features that include exterior or support, typicallymolded-in-place are shown and described. In the embodiments of FIGS.48-57, on the other hand, variations are shown in which the safety orsecondary cartridge is not configured from an analogous mediaconfiguration, but rather comprises a media definition that does notsubstantially vary along its length, with respect to pleat or depthdefinition. Such safety filter cartridges can have an end remote fromthe seal location, which is generally circular, but which includes acentral projection analogously configured for engagement with variousother structure in the system. The seal arrangement can be an o-ring,but examples are depicted in which it is molded-in-place, at an endremote from the closed end. With such an assembly, a cartridge supportwithin the housing can be configured appropriately for engagement withsuch a cartridge.

Regardless of the particular shape of safety cartridge used in a givensystem, the selected principles described herein can be applied toprovide a cushion member or grommet member than can be applied tocushion a preferred interaction among: a central housing support; thesafety filter cartridge; and, a main filter cartridge. Examples of suchcushion members are described, for example, in connection with FIGS.16-57. In previously described embodiments, cushion members are depictedthat can be applied in different ways, and general to manage interactionbetween the tower and the safety cartridge, but not necessarily the maincartridge.

B. Features Relating to Support of Main Filter Cartridge in a CushionManner

It is noted that the features applied herein can even be used to supporta main filter cartridge in a cushion manner, even when a safetycartridge is not present; or, when a safety cartridge is present, but itdoes not specifically engage the main filter cartridge, along a grommetmember positioned therein. These variations can be accomplished, bymounting an appropriate cushion/grommet member on a tower supportpositioned in the housing, but separate from any safety cartridgepresent (if one is present at all). When such is the case, a cartridgeanalogous to those main filter cartridges described herein, could bepushed over the grommet, with the cushion engagement occurring. Agrommet with an outer perimeter analogous to those described for thearrangements described in FIGS. 16-57 could be applied in this instance,except for grommet mounting on a support that is not necessarily asafety cartridge. In such instances, a safety cartridge could even beused, as a media member pushed over the support but not having an endwith a grommet mounted thereon.

C. Variations that Relate to Desired Flexibility in Length

In some instances, it is desired to vary the length of the main filtercartridge in the overall housing. Referring to the arrangement of FIG.16, this could be accomplished, for example, by having a long mainfilter cartridge 403 and a longer housing 402, in an axial direction,while using a same support 407 and safety 404. This can be accomplishedby having the portions of the access cover and main filter cartridgethat engage the safety and tower, project further toward the outlet endof the housing. An example of how this can be accomplished can beunderstood by comparing, for example the cross-section of FIG. 11 andthe cross-section of FIG. 80.

From this, it can be understood that the same housing body, tower, andsafety can be used in a system that is varied with respect to axiallength of the main filter cartridge and overall housing.

D. Application of Principles with Variations in Diameter

The principles and techniques described herein can be applied in systemswith a variety of alternate diameters of cartridges and othercomponents. They can be managed in a “modular” manner, if those featuresthat relate to interaction among the closes the main filter cartridge,and structure within the housing, such as a safety cartridge and centralsupport are maintained with similar dimension to those described.

E. Features that Relate to Ensuring the Main Filter Cartridge is anAppropriate One for the System of Use

Many of the features that relate to interaction of the main filtercartridge with the remainder of the assembly that are described herein,in connection with the various embodiments, relate to helping to ensurethat the main filter cartridge is a proper one for the system in whichit is installed. This can be managed by controlling dimension of thoseportions that interact axially or radially. Preferred dimensions andcharacterizations with respect to those features described herein, canbe used to advantage with respect to accomplishing this.

F. Some Selected Preferred Methods

Also, characterized herein are methods of installation of a main filtercartridge into an assembly. Typically, the main filter cartridge wouldbe as characterized, and is installed until a housing seal adjacent anopen end of the cartridge fully engages in a sealing, in a releasablemanner, a portion of a housing in which it is pushed. At the same time,preferably in an interior of a projection member at an opposite end ofthe cartridge is pushed over a cushion member until stabilizing,releasable, interfering engagement occurs. This is shown in various onesof the figures.

VII. Summary Comments and Observations

1. A filter cartridge characterized by:(a) an extension of media surrounding an open interior and having afirst end and a second end; (i) at the first end, the media having nopleat greater than 3 mm in depth; and, (ii) at the second end, the mediacomprising a plurality of pleats each having a pleat depth of at least10 mm.2. A filter cartridge according to characterization 1 wherein: (a) theextension of media surrounds a central axis; (i) the media being pleatedadjacent the second end and defining a plurality of inner pleat tipsextending at an acute angle, relative to a plane perpendicular to acentral axis, of no greater than 89°, in extension toward the first end;and, (ii) the media being non-pleated at the first end.3. A filter cartridge according to any one of characterizations 1 and 2including: (a) a radially directed housing seal member positioned at alocation within 50 mm of the first end of the extension of media; (i)the filter cartridge having a maximum, undistorted, radial widthdimension, at a location in radial overlap with the media and thehousing radial seal member, of at least 10 mm less than a maximum pleatdepth of the extension of media adjacent the second end of the extensionof media.4. A filter cartridge according to any one of characterizations 1-3including: (a) a media support; (i) the media including a non-pleated,free, tip section adjacent the media first end that extends, axially, ina direction away from the second end, an axial distance of at least 0.5mm beyond a nearest adjacent portion of the media support.5. A filter cartridge characterized by: (a) an extension of mediasurrounding a central axis and defining an open interior; (i) the mediahaving first and second ends; and, (ii) the media being pleated adjacentthe second end and defining a plurality of inner pleat tips extending atan acute angle, relative to a plane perpendicular to a central axis, ofno greater than 89°, in extension toward the first end; and, (iii) themedia being non-pleated at the first end.6. A filter cartridge according to any one of characterizations 1-5including: (a) a housing radial seal member positioned at a locationwithin 40 mm of the first end.7. A filter cartridge characterized by: (a) an extension of mediasurrounding an open interior and having a first end and a second end;(i) the media comprising a plurality of pleats each having a pleat depthdecreasing in extension from the second end in a direction toward thefirst end; and, (b) a housing radial seal member positioned at alocation within 50 mm of the first end.8. A filter cartridge according to any one of characterizations 1-7wherein: (a) the media surrounds and defines a central cartridge axis;and, (b) the media includes a plurality of inner pleats having innerpleat tips extending at an acute angle of no more than 88°, relative toa plane perpendicular to a central axis, in extension toward the firstend.9. A filter cartridge according to any one of characterizations 1-8wherein: (a) the media surrounds and defines a central cartridge axis;and, (b) the media includes a plurality of inner pleats having innerpleat tips extending at an acute angle within the range of 70°-88°,inclusive, relative to a plane perpendicular to the central axis, inextension toward the first end.10. A filter cartridge according to any one of characterizations 1-9wherein: (a) the media surrounds and defines a central cartridge axis;and, (b) the media includes a plurality of outer pleats and a pluralityof inner pleats; (i) the inner pleats including a plurality of innerpleat tips extending at a first angle relative to a plane perpendicularto the central axis, in extension from the second end toward the firstend; and, (ii) the outer pleats including a plurality of outer pleatstips extending at a second angle, relative to a plane perpendicular tothe central axis, in extension from the second end toward the first end;(ii) the second angle being greater than the first angle, with respectto a plane perpendicular to the central axis.11. A filter cartridge according to any one of characterizations 1-10wherein: (a) the media surrounds and defines a central cartridge axis;and, (b) the media includes a plurality of outer pleats having outerpleat tips extending at an angle within the range of 88°-90°, inclusive,relative to a plane perpendicular to the central axis, in extension fromthe second end toward the first end.12. A filter cartridge characterized by: (a) an extension of mediahaving a first end and a second end; (i) the media surrounding anddefining an open interior; (ii) adjacent the second end, the extensionof media being pleated; and, (b) a radially directed housing seal memberpositioned at a location within 50 mm of the first end of the extensionof media; (i) the filter cartridge having a maximum, undistorted, radialwidth dimension, at a location in radial overlap with the media and thehousing radial seal member, of at least 10 mm less than a maximum pleatdepth of the extension of media adjacent the second end of the extensionof media.13. A filter cartridge characterized by: (a) an extension of mediasurrounding an open interior and having a first end and a second end;(i) the media, adjacent the second end, being pleated and comprising aplurality of outwardly directed pleats and a plurality of inwardlydirected pleats; and, (ii) each one of the plurality of outwardlydirected pleats having a pleat tip with an outer perimeter tip shape,(iii) an inner perimeter tip shape, of each pleat tip of the pluralityof inwardly directed pleats, being narrower than the pleat tip shape ofeach one of the plurality of outwardly directed pleats; (A) the outerpleat tips having an outer, perimeter, pleat shape at a locationadjacent the second end with a radius of at least 4 mm.14. A filter cartridge according to any one of characterizations 1-13including: (a) a radially directed housing seal member at a locationwithin 40 mm of the first end of the media.15. A filter cartridge according to any one of characterizations 1-14including: (a) a radially directed housing seal member positioned within30 mm of the first end of the media.16. A filter cartridge according to any one of characterizations 1-15including: (a) a radially directed housing seal member positioned at alocation within 20 mm of the first end of the media.17. A filter cartridge according to any one of characterizations 1-16including: (a) a radially directed housing seal member positioned at alocation within 15 mm of the first end of the media.18. A filter cartridge according to any one of characterizations 1-17including: (a) a radially outwardly directed housing seal member.19. A filter cartridge characterized by: (a) an extension of mediasurrounding an open interior and having a first end and a second end;(i) the extension of media being pleated adjacent the second end; and,(b) a media support; (i) the media including a non-pleated, free, tipsection adjacent the media first end that extends, axially, in adirection away from the second end, an axial distance of at least 0.5 mmbeyond a nearest adjacent portion of the media support.20. A filter cartridge characterized by: (a) an extension of pleatedmedia having a first end and a second end; (i) the extension of mediasurrounding an open filter interior; and, (b) a media support includinga first, intermediate, outer pleat spacer positioned between the mediafirst end and the media second end; (i) the first, intermediate, outerpleat spacer defining an outer pleat engagement shape with an outerpleat radius of at least 4 mm; and, (ii) the first, intermediate, outerpleat spacer having radial projections defining inner pleat engagementtips having an outer pleat angle of at least 30°.21. A filter cartridge characterized by: (a) an extension of mediahaving first end and a second end; (i) the extension of media comprisinga plurality of pleats adjacent the second end; and, (ii) the mediasurrounding a central axis and defining an open interior; and, (b) aplurality of intermediate outer pleat spacers positioned between themedia first and second ends; (i) axially spaced, adjacent, ones of theplurality of intermediate outer pleat spacers having different amountsof radial projection extension toward the central axis.22. A filter cartridge characterized by: (a) an extension of mediahaving a first end and a second end; (i) the extension of mediacomprising a plurality of pleats adjacent the second end; and, (ii) themedia surrounding and defining an open interior; and, (b) a mediasupport including longitudinal ribs extending along, and secured to,outer pleat tips of the media in extension from the second end of themedia toward the first end of the media, along at least 50% of a lengthof extension of the outer pleat tips.23. A filter cartridge characterized by: (a) media extending betweenfirst and second ends and surrounding and defining a central axis andopen interior; and, (b) an end piece adjacent the second end of themedia; (i) the end piece defining an outer perimeter of alternatingradial outward projections and radial inward recesses; and, (ii)adjacent ones of the outward projections being spaced by a radial gap ofat least 30°.24. A filter cartridge characterized by: (a) media extending betweenfirst and second ends and surrounding and defining a central axis and anopen central interior; and, (i) the media being pleated adjacent thesecond end; and, (b) an end piece adjacent the second end of the media;(i) the end piece defining an outer perimeter of alternating radialouter projections and radial inward recesses; and, (ii) the end pieceradial inward recesses being open, in axial overlap with spaces betweenouter pleats, by a gap of at least 15 mm in maximum width at a locationremote from inner pleat tips.25. A filter cartridge characterized by: (a) media extending betweenfirst and second media ends and surrounding and defining a central axisand an open central interior; and, (b) an end piece adjacent to, andextending across, the second media end;the end piece including: an outer surface directed away from the firstmedia end; and, an inner surface directed toward the first media end;(i) the inner surface of the end piece having a central recess thereinextending in a direction away from the first media end; and, (c) acushion member positioned with at least a portion thereof in the centralrecess.26. A filter cartridge characterized by: (a) an extension of mediahaving a first end and a second end and surrounding a central axis and acentral interior; (b) a media support including an end piece adjacent tothe second media end; (i) the end piece having a central projection withan aperture therethrough; and, (c) a radially outwardly directed housingradial seal member positioned on, and surrounding, the media support ata location within 50 mm of the first end of the media.27. A filter cartridge characterized by: (a) media extending betweenfirst and second ends and surrounding and defining a central axis and anopen central interior; and, (b) an end piece adjacent the second end ofthe media; (i) the end piece having an inner surface with a centralrecess therein; (ii) the central recess being defined by a projectionextending away from the media first end having a wall surrounded by, andspaced from, the media; and, (iii) the projection having a tip, remotefrom the media first end, with an aperture therethrough.28. A filter cartridge according to any one of characterizations 26-27wherein: (a) a cushion member is positioned extending through theaperture in the central projection.29. A filter cartridge according to characterization 28 wherein: (a) thecushion member is closed.30. A filter cartridge according to any one of characterizations 28 and29 wherein: (a) the cushion member includes a housing engagement cushionportion at a location outside of the central projection and having alargest cross-dimension than a tip of the central projection.31. A filter cartridge according to any one of characterizations 23-30wherein: (a) the media is pleated adjacent the second end.32. A filter cartridge according to characterization 31 wherein: (a) themedia, adjacent the second end, includes a plurality of inner pleat tipsextending at an angle of no greater than 88°, relative to a planeperpendicular to the central axis, in extension from the second endtoward the first end.33. A filter cartridge according to any one of characterizations 1-32wherein: (a) the first end of the media is not pleated.34. A filter cartridge according to any one of characterizations 1-33wherein: (a) at the second end, the media is pleated with a pleat depthof at least 10 mm.35. A filter cartridge according to any one of characterizations 1-34wherein: (a) at the second end, the media is pleated with a pleat depthof at least 15 mm.36. A filter cartridge according to any one of characterizations 1-35wherein: (a) at the second end, the media is pleated with a pleat depthwithin the range of 10 to 40 mm, inclusive.37. A filter cartridge according to any one of characterizations 1-36wherein: (a) the media includes a plurality of outer pleats adjacent thesecond end; each one of the plurality of outer pleats having an outerpleat tip extending at an acute angle of at least 86°, in extensiontoward the second end, relative to a plane perpendicular to the centralaxis.38. A filter cartridge according to any one of characterizations 1-37wherein: (a) the media includes a plurality of outer pleats adjacent thesecond end; each one of the plurality of outer pleats having an outerpleat tip extending and an acute angle of at least 87°, in extensiontoward the second end, relative to a plane perpendicular to the centralaxis.39. A filter cartridge according to any one of characterizations 1-38wherein: (a) the media includes a plurality of outer pleats adjacent thesecond end; each one of the plurality of outer pleats having an outerpleat tip extending at an acute angle within the range of 87−90°,inclusive, in extension toward the second end, relative to a planeperpendicular to the central axis.40. A filter cartridge according to any one of characterizations 1-39wherein: (a) the media comprises a plurality of inner pleats adjacentthe second end, each one of plurality of inner pleats having an innerpleat tip that extend at an angle of no greater than 87°, relative to aplane perpendicular to the central axis, in extension toward the firstend.41. A filter cartridge according to any one of characterizations 1-40wherein: (a) the media comprises a plurality of outer pleats with outerpleat tips and a plurality of inner pleats with inner pleat tips; (i)the inner pleat tips extending at a first angle relative to a planeperpendicular to the central axis, in extension from the second endtoward the first end; and, (ii) the outer pleat tips extending at asecond angle, relative to a plane perpendicular to the central axis, inextension from the second end toward the first end; (iii) the firstangle being at least 2° less than the second angle.42. A filter cartridge according to characterization 41 wherein: (a) thefirst angle is at least 3° less than the second angle.43. A filter cartridge according to any one of characterizations 41 and42 wherein: (a) the first angle is at least 4° less than the secondangle.44. A filter cartridge according to any one of characterizations 1-43wherein: (a) the filter cartridge is open at an end adjacent the firstend of the media.45. A filter cartridge according to any one of characterizations 1-44including: (a) a radially directed housing seal arrangement.46. A filter cartridge according to characterizations 45 wherein: (a)the radially directed housing seal arrangement is a radially outwardlydirected housing seal arrangement.47. A filter cartridge according to any one of characterizations 1-46including: (a) a radially directed housing seal arrangement comprisingan o-ring.48. A filter cartridge according to any one of characterizations 1-47including: (a) a media support extending from the second end toward thefirst end of the media.49. A filter cartridge according to characterization 48 wherein: (a) themedia has an outer surface and an inner surface; (b) the media supporthas first and second ends; and, (c) the media support extends along theouter surface of the media, with no radial support for the media thatextends at least 50% of a distance between the first and second ends ofthe support, that is also positioned projecting radially inwardly fromadjacent portions of the media inner surface.50. A filter cartridge according to any one of characterizations 48 and49 wherein: (a) the media support includes: an open end within 20 mm ofmedia first end; and, an end piece adjacent the media second end.51. A filter cartridge according to characterization 50 wherein: (a) theend piece of the media support includes a central aperture therethroughthat is lined with a resilient cushion member.52. A filter cartridge according to any one of characterizations 50 and51 wherein: (a) the end piece of the media support comprises an endpiece having an outer perimeter of alternating radial projections andradial recess; the radial recesses extending radially inwardly at least10 mm from the outermost portions of the radial projections.53. A filter cartridge according to any one of characterizations 50-52wherein: (a) the end piece of the media support comprises an end piecehaving an outer perimeter of alternating radial projections and radialrecess; the radial recesses extending radially inwardly at least 15 mmfrom the outermost portions of the radial projections.54. A filter cartridge according to any one of characterizations 50-53wherein: (a) the end piece of the media support comprises an end piecehaving an outer perimeter with a plurality of radial recesses therein;each one of the plurality of radial recesses extending toward a centralaxis by at least 30% of a radial distance between an outermost portionof the closed end of the media support and the central axis.55. A filter cartridge according to any one of characterizations 50-54wherein: (a) the end piece of the media support comprises an end piecehaving an outer perimeter with a plurality of radial recesses therein;each one of the plurality of radial recess extending toward a centralaxial by at least 35% of a radial distance between an outermost portionof the closed end of the media support and the central axis.56. A secondary filter cartridge according to any one ofcharacterizations 50-55 wherein: (a) the end piece of the media supportcomprises an end piece having an outer perimeter with a plurality ofradial recesses therein; each one of the plurality of radial recessesextending toward a central axis by at least 40% of a radial distancebetween an outermost portion of the closed end of the media support andthe central axis.57. A filter cartridge according to any one of characterizations 50-56wherein: (a) the end piece of the media support includes an innersurface with an axially projecting receiver recess therein; (i) theaxially projecting receiver recess projecting axially in a directionaway from a first end of the media.58. A filter cartridge according to any one of characterizations 50-57wherein: (a) the end piece of the media support includes an outersurface with a central receiving groove therein surrounding an outer,central, projection; (i) the outer, central, projection projecting in adirection axially away from the first end of the media.59. A filter cartridge according to characterization 58 wherein: (a) theouter, central, projection includes an aperture therethrough, that islined with a resilient cushion member.60. A filter cartridge according to any one of characterizations 58 and59 wherein: (a) the central receiving groove is at least 5 mm deep, inaxial direction toward the first end of the media, from any immediatelysurrounding portion of the closed end of the media support.61. A filter cartridge according to any one of characterizations 58-60wherein: (a) the outer central projection projects to a tip locatedaxially beyond the second end of the media, from the first end of themedia.62. A filter cartridge according to any one of characterizations 58-61wherein: (a) the outer central projection projects to a tip at least 5mm from an immediately surrounding portion of the closed end, in adirection axially away from the open end.63. A filter cartridge according to any one of characterizations 58-62wherein: (a) the outer central projection projects to a tip located atleast 10 mm from an immediately surrounding portion of the end piece ina direction axially away from the open end.64. A filter cartridge according to any one of characterizations 58-63wherein: (a) the media support includes a plurality of longitudinal ribsextending in a direction from the second end of the media toward thefirst end on the media.65. A filter cartridge according to characterization 64 wherein: (a)each one of the plurality of longitudinal ribs extends along, andengages, an outer pleat tip of the media.66. A filter cartridge according to any one of characterizations 58-65wherein: (a) the media support includes at least one intermediate pleatspacer surrounding an outer surface of the media and having radialprojections extending between adjacent media pleats.67. A filter cartridge according to any one of characterizations 58-63wherein: (a) the media support includes a plurality of intermediatepleat spacers surrounding an outer surface of the media and havingradial projections extending between adjacent media pleats.68. A filter cartridge according to any one of characterizations 1-67including: (a) a seal support ring surrounding the media within 50 mm ofthe media first end; (i) the seal support ring including an o-ringreceiving groove therein; and, (ii) the seal support ring including aplurality of spaced radial expansion gussets tapering radially inwardlyalong a direction of extension from a location adjacent the o-ringreceiving groove toward the first end of the media.69. A filter cartridge according to any one of characterizations 1-68including: (a) an end piece adjacent to the second media end; the endpiece including: an outer surface directed away from the first mediaend; and, an inner surface directed toward the first media end; (i) theinner surface of the end piece having a central recess therein extendingin a direction away from the media end; (ii) the central recess beingdefined by a central projection having a tip with an aperturetherethrough; and, (b) a resilient cushion member arrangement positionedin the central recess and projection through, and closing, the aperturein the tip of the central projection; (i) the cushion member arrangementdefining a cushion receiver region within the central recess; and, (ii)the cushion member arrangement including an outer radial projectionmember positioned at an opposite side of the aperture from the centralrecess.70. A filter cartridge characterized by: (a) an extension of mediasurrounding an open interior and having a first end and a second end;(b) an end piece adjacent to the second media end; the end pieceincluding: an outer surface directed away from the first media end; and,an inner surface directed toward the first media end; (i) the innersurface of the end piece having a central recess therein extending in adirection away from the media end; (ii) the central recess being definedby a central projection having a tip with an aperture therethrough; and,(c) a cushion member arrangement positioned in the central recess andprojections through, and closing, the aperture in the tip of the centralprojection; (i) the cushion member arrangement defining a cushionreceiver region within the central recess; and, (ii) the cushion memberarrangement including an outer radial projection member positioned at anopposite side of the aperture from the central recess.71. A filter cartridge according to any one of characterizations 69 and70 wherein: (a) the radial projection member of the cushion memberarrangement has a largest radial cross-dimension of at least 15 mm.72. A filter cartridge according to any one of characterizations 69-71wherein: (a) the radial projection member of the cushion memberarrangement has a largest radial cross-dimension of at least 18 mm.73. A filter cartridge according to any of characterizations 69-72wherein: (a) the radial projection member of the cushion memberarrangement has a largest radial cross-dimension within the range of15-30 mm.74. A filter cartridge according to any one of characterizations 69-73wherein: (a) the radial projection member of the cushion memberarrangement has a largest radial cross-dimension of no greater than 25mm.75. A filter cartridge according to any one of characterizations 69-74wherein: (a) the radial projection member of the cushion memberarrangement has a largest radial cross-dimension at least 0.5 mm largerthan the tip of the central projection.76. A filter cartridge according to any one of characterizations 69-75wherein: (a) the radial projection member of the cushion memberarrangement has a largest radial cross-dimension at least 1 mm largerthan the tip of the central projection.77. A filter cartridge according to any one of characterizations 64-76wherein: (a) the radial projection member of the cushion memberarrangement has a circular outer perimeter.78. A filter cartridge according to any one of characterizations 69-74wherein: (a) the cushion member arrangement comprises a singleintegrally molded grommet member.79. A filter cartridge according to any one of characterizations 69-78wherein: (a) the cushion member arrangement comprises a single grommethaving a hardness of no greater than 80 Shore A.80. A filter cartridge according to any one of characterizations 69-79wherein: (a) the cushion member arrangement comprises a single grommethaving a hardness within the range of 50-80 Shore A.81. A filter cartridge according to characterization 70 wherein: (a) theend piece adjacent to the second media end has a circular outerperimeter.82. A filter cartridge according to characterization 81 wherein: (a) themedia is pleated with a pleat depth that does not vary in extension fromthe first end to the second end.83. A filter cartridge according to any one of characterizations 70-82wherein: (a) the central projection, on the end piece adjacent to thesecond media end, is surrounded by a receiving groove positioned aroundthe central projection and having an outer wall spaced from the centralprojection to provide a cross-dimension at an inner end of the groove ofat least 4 mm and no more than 25 mm, at a location adjacent aninnermost end of the central projection.84. A filter cartridge according to any one of characterizations 70-83wherein: (a) the media is pleated with a pleat depth that does not varyin extension from the first end to the second end.85. A gas filter assembly characterized by: (a) a housing defining: aninterior, a gas flow inlet; and, a gas flow outlet; (i) the housingincluding a housing base section and a removable access cover; (b) asafety filter cartridge according to at least one of claims 1-84operably and removably positioned within the housing interior; and, (c)a main filter cartridge comprising media surrounding an open filterinterior; (i) the main filter cartridge being operably and removablypositioned within the housing interior with media of the safetycartridge projecting into the open filter interior of the main filtercartridge.86. A gas filter assembly according to characterization 85 wherein: (a)the housing includes a central cartridge support in the housing basesection directed toward the access cover; and, (b) the safety filtercartridge is positioned with the central cartridge support projectinginto an open filter interior of the safety filter cartridge.87. A gas filter assembly according to characterization 86 wherein: (a)the central cartridge support includes a central cartridge support enddirected toward the access cover; (i) the central cartridge support endincluding a central projection thereon; and, (b) the safety filtercartridge includes an inner surface having a receiver recess into whichthe central projection on the central cartridge support extends; (i) aresilient cushion member being provided with a portion in the receiverrecess of the safety filter cartridge and around the central projectionon the central cartridge support.88. A gas filter assembly according to any one of characterizations 86and 87 wherein: (a) the central cartridge support includes a centralcartridge support end directed toward the access cover; (i) the centralcartridge support end including a central projection thereon; and, (b)the safety filter cartridge including an end directed toward the accesscover with a projection having a tip with an aperture therethrough; (i)the central projection on the central cartridge support projectingcompletely through the aperture in the tip of the projection in thesafety filter cartridge.89. A gas filter assembly according to characterization 88 wherein: (a)the aperture in the tip of the projection in the safety filter cartridgeis closed by a resilient cushion member that projects through theaperture.90. A gas filter assembly according to any one of characterizations87-89 including: (a) a resilient cushion member on the safety filtercartridge in releasable sealing engagement around the central projectionon the central cartridge support.91. A gas filter assembly according to any one of characterizations88-90 wherein: (a) the central projection on the central cartridgesupport includes a tip and a neck section; (i) the neck section having anarrower cross-sectional dimension than a dimension of the centralprojection, on the central cartridge support, adjacent the tip.92. A gas filter assembly according to characterization 91 wherein: (a)an interference fit is provided between the tip of the centralprojection on the central cartridge support, and the safety filtercartridge, by the tip and the neck section.93. A gas filter assembly according to any one of characterizations87-90 wherein: (a) a resilient cushion member on the safety filtercartridge comprises a grommet projecting through an aperture in a tip ofthe central projection on the cartridge support; (i) the grommet closingthe aperture in the tip; (b) the grommet including an outer radialprojection member positioned on opposite side of the aperture from thecentral recess; and, (c) the main filter cartridge including an end witha receiver therein positioned surrounding, and in interferenceengagement with, the outer radial projection member of the grommet.94. A gas filter assembly according to characterization 93 wherein: (a)the outer radial projection member of the grommet is contacted by thereceiver on the main filter cartridge with a continuous 360° contactaround a central axis.95. A gas filter assembly according to any one of characterizations85-94 wherein: (a) the housing includes a seal flange surrounding asafety filter cartridge end receiver recess; and, (b) the safety filtercartridge is positioned with the media first end projecting into thesafety filter cartridge end receiver recess.96. A gas filter assembly according to characterization 95 wherein: (a)the safety filter cartridge end receiver recess has a maximum radialwidth of no greater than 15 mm; and, (b) the safety filter cartridgeincludes media having a pleat depth, adjacent a second end, of greaterthan 15 mm.97. A gas filter assembly according to any one of characterizations 95and 96 wherein: (a) at the media first end, the safety filter cartridgeis non-pleated.98. A gas filter assembly according to any one of characterizations95-97 wherein: (a) the media first end, of the safety filter cartridge,is a free end having a tip of extension of at least 0.5 mm with no endcap thereon, and no media support structure, of the safety filtercartridge, positioned radially thereagainst.99. A gas filter assembly according to any one of characterizations95-98 wherein: (a) the safety filter cartridge end receiver recess ispositioned between the seal flange and a base end of a central cartridgesupport; (i) the central cartridge support being separate from thesafety filter cartridge and being positioned in the housing at alocation projecting toward the access cover.100. A gas filter assembly according to any one of characterizations85-99 wherein: (a) the media of the main filter cartridge has a firstend and a second end; (i) the media of the main filter cartridge havingan internal perimeter that decreases in cross-sectional dimension inextension from the first end to the second end.101. A gas filter assembly according to characterization 100 wherein:(a) the main filter cartridge includes a first end piece adjacent thefirst end and a second end piece positioned toward the second end; (i)the first end piece being open; and, (ii) the second end piece beingclosed and including a central projection thereon projecting from thesecond end of the media toward the first end of the media at least 15%of a distance from the second end of the media toward the first end ofthe media.102. A gas filter assembly according to any one of characterizations85-101 wherein: (a) the main filter cartridge includes a first end pieceadjacent the first end and a second end piece spaced toward the secondend; (i) the first end piece being open; and, (ii) the second end piecebeing closed and including a central projection thereon projecting fromthe second end of the media toward the first end of the media at least20% of a distance from the second end of the media toward the first endof the media.103. A gas filter assembly according to any one of characterizations100-102 wherein: (a) the safety filter cartridge projects into the openfilter interior of the main filter cartridge to a location no more than90% of a distance from the first end of the main filter cartridge mediato the second end of the main filter cartridge media.104. A gas filter assembly according to any one of characterizations100-103 wherein: (a) the safety filter cartridge projects into the openfilter interior of the main filter cartridge to a location no more than85% of a distance from the first end of the main filter cartridge mediato the second end of the main filter cartridge media.105. A gas filter assembly according to any one of characterizations100-104 wherein: (a) at a location around the second end of the media ofthe safety cartridge, a clearance between the main filter cartridge andthe safety cartridge is no more than 8 mm.106. A gas filter assembly according to any one of characterizations85-105 wherein: (a) the housing includes a central cartridge support, inthe housing base section, directed toward the access cover; (b) thesafety filter cartridge is positioned with the central cartridge supportprojecting into an open filter interior of the safety filter cartridge;(c) the safety filter cartridge includes an end, directed toward theaccess cover, having a recess into which the central projection on thecartridge support extends; (i) the receiver recess in the safety filtercartridge being defined by a projection directed toward the accesscover; (d) a resilient cushion member being provided in the receiverrecess of the safety filter cartridge and around the central projectionon the central cartridge support; and, (e) the main filter cartridgeincludes a closed end piece having an inner surface with a receiverrecess therein; (i) the central projection on the cartridge support, andthe projection on the safety filter cartridge, defining the receiverrecess in the safety filter cartridge, projecting into the receiverrecess in the inner surface of the closed end piece of the main filtercartridge.107. A gas filter assembly according to any one of characterizations85-106 wherein: (a) the housing includes a central cartridge support inthe housing base section directed toward the access cover; (b) thesafety filter cartridge is positioned with the central cartridge supportprojecting into an open filter interior of the safety filter cartridge;(c) a resilient cushion member is provided in the receiver recess of thesafety filter cartridge around the central projection on the centralcartridge support; (d) the safety filter cartridge includes an enddirected toward the access cover having an outer surface with a receivergroove surrounding a central projection; and, (e) the main filtercartridge includes a closed end piece having an inner surface with aprojection extending into the receiver groove on the outer surface ofthe safety cartridge end.108. A gas filter assembly characterized by: (a) a housing defining aninterior, a gas flow inlet; and, a gas flow outlet; (i) the housingincluding a housing base section and a removable access cover; (ii) thehousing including a central cartridge support in the housing basesection directed toward the access cover; (b) a safety filter cartridgepositioned over the central cartridge support; the safety filtercomprising media having first and second ends, surrounding a centralaxis and defining an open interior; (i) at the first end, the mediahaving no pleat greater than 3 mm in depth; and, (ii) at the second end,the media comprising a plurality of pleats each having a pleat depth ofat least 10 mm; (c) a main filter cartridge comprising media surroundinga central axis end defining an open interior; (i) the media beingpleated in extension between first and second ends; (ii) the mediatapering inwardly in extension from the first end toward the second end;(iii) the main filter cartridge including a first, open, end piece onthe media first end; (A) a radially inwardly directed housing seal beingpositioned on the first end piece; and, (iv) the main filter cartridgeincluding a closed end piece on the media second end; (A) the closed endpiece including a central projection extending toward the first end ofthe media to a location at least 15% of a distance between the mediasecond end and the media first end.109. A gas filter assembly according to characterizations 108 wherein:(a) the closed end piece including a central projection extending towardthe first end of the media to a location at least 20% of a distancebetween the media second end and the media first end.110. A gas filter assembly according to any one of characterizations 108and 109 wherein: (a) the closed end piece including a central projectionextending toward the first end of the media to a location at least 25%of a distance between the media second end and the media first end.111. A gas filter assembly according to any one of characterizations108-110 wherein: (a) the safety filter cartridge is in accord with anyone of characterizations 1-84.112. A gas filter assembly according to any one of characterizations108-111 wherein: (a) the assembly is also in accord with any one ofcharacterizations 85-107.113. A gas filter assembly characterized by: (a) a housing defining: aninterior; a gas flow inlet; a gas flow outlet; and, a seal flange; (i)the housing including a housing base section and a removable accesscover; (b) a main filter cartridge support positioned in the housinginterior; (i) the main cartridge support including an end remote fromthe gas flow outlet; (c) a resilient cushion member positioned on theend of the main cartridge support remote from the gas flow outlet; (i)the resilient cushion member including an outer radial projectionmember; and, (d) a main filter cartridge comprising media surrounding anopen filter interior; (i) the media extending between first and secondends; (ii) the main filter cartridge including an open end having ahousing seal member thereon, adjacent the media first end; (A) thehousing seal member comprising a radially directed seal member; (iii)the main filter cartridge includes a closed end remote from the openend; (A) the filter cartridge closed end including a receiver thereinpositioned surrounded by, and in releasable interference engagementwith, the outlet radial projection member.114. A gas filter assembly according to characterization 113 wherein:(a) the main filter cartridge support comprises a safety filtercartridge removably positioned within the gas filter assembly.115. A gas filter assembly according to characterization 114 wherein:(a) the safety filter cartridge is in accord with any one ofcharacterizations 1-84.116. A gas filter assembly according to any one of characterizations114-115 wherein: (a) the housing includes a central cartridge support;and, (b) the safety filter is removeably positioned over the centralcartridge support.117. A gas filter assembly according to any one of characterizations114-116 wherein: (a) the assembly is also in accord with any one ofcharacterizations 85-112.118. A gas filter assembly in accord with any one of characterizations113-117 wherein: (a) the main filter cartridge is in accord withcharacterization 125.119. A gas filter assembly according to characterization 118 wherein:(a) the main filter cartridge is in accord with any one ofcharacterizations 126-136.120. A gas filter assembly in accord with any one of characterizations118-119 wherein: (a) the main filter cartridge is in accord with any oneof characterizations 136-138.121. A gas filter assembly in accord with any one of characterizations118-120 wherein (a) the main filter cartridge is in accord with any oneof characterizations 139-141.122. A gas filter assembly in accord with any one of characterizations115-121 wherein: (a) the main filter cartridge is installed in accordwith the method of characterizations 142.123. A housing for a gas filter assembly; the housing: (a) defining aninterior and a gas flow outlet; (i) the housing including a housing basesection and a removable access cover; (b) the housing including acentral cartridge support in the housing base section directed towardthe access cover; and, (c) the central cartridge support includes acartridge support end directed toward the access cover having a centralprojection with an end tip and a neck section; (i) the neck sectionhaving a narrower cross-sectional dimension than a dimension of thecentral projection on the central cartridge support, adjacent the endtip.124. A housing according to characterization 123 including: (a) a sealflange surrounding an end of the central cartridge support defining asafety filter cartridge and receiver recess having a maximum radialwidth of no greater than 25 mm.125. A main air filter cartridge for removable installation in an aircleaner housing over, and in releasable support engagement with, acushion member positioned within the air cleaner housing; the main airfilter cartridge comprising: (a) media surrounding and defining an openinterior and a central axis; (i) the media extending between first andsecond ends; (b) a first end piece at the first end of the media; (i)the first end piece having a central air flow aperture therethrough, incommunication with the open filter interior; (c) a radially directedhousing seal arrangement on the first end piece and surrounding thecentral air flow aperture; (d) a central closure member extendingacross, and closing, the filter cartridge at a location spaced towardthe second end of the media from the first end of the media; (i) thecentral closure member having an inner surface and an outer surface;(ii) the inner surface of the central closure member defining a centralrecess therein, defined by an inner surface of a surrounding centralprojection on the outer surface; (A) the central recess includingresilient cushion member engagement sidewall portion having a largestcross-section dimension of within the range of 12-26 mm at a selectedlocation for releasable supported engagement with a resilient cushionmember positioned in a housing, during installation; (iii) the outersurface of the central closure member having a receiving groove therein,surrounding the central projection; (A) the receiving groove beingdefined between inner and outer sidewalls, joined at a ring tip; (1) theinner sidewall comprising a portion of the central projection; (2) thering tip having an outer width of no greater than 30 mm; and, (3) thegroove being at least 10 mm deep with respect to the outer sidewall.126. A main filter cartridge according to characterization 125 wherein:(a) the resilient cushion member engagement sidewall portion defines aninner surface section having a circular cross-section taken in directionperpendicular to the central axis.127. A main filter cartridge according to any one of characterizations125 and 126 wherein: (a) the resilient cushion member engagementsidewall portion defines an inner surface section having a taper angle,relative to a central axis, within the range of 0.5°-7,° inclusive, at alocation that is engaged by a resilient cushion member, duringinstallation.128. A main filter cartridge according to characterization 127 wherein:(a) the resilient cushion member engagement sidewall portion defines aninner surface section having a taper angle of at least 1°, at a locationthat is engaged by a resilient cushion member, during installation.129. A main filter cartridge according to any one of characterizations127 and 128 wherein:

(a) the receiving groove is no greater than 30 mm wide at an innermostportion thereof.

130. A main filter cartridge according to any one of characterizations128 and 129 wherein: (a) the receiving groove is no greater than 25 mmwide at an innermost portion thereof 131. A main filter cartridgeaccording to any one of characterizations 129 and 130 wherein: (a) thereceiving groove is no greater than 12 mm wide.132. A main air filter cartridge according to any one ofcharacterizations 125-131 wherein: (a) the outer sidewall, of thereceiving groove, has an outward taper at an angle of at least 40°relative to a plane perpendicular to the central axis.133. A main air filter cartridge according to characterization 132wherein: (a) the outer sidewall, of the receiving groove, has an outwardtaper at an angle of at least 50° relative to a plane perpendicular tothe central axis.134. A main air filter cartridge according to characterization 132wherein: (a) the outer sidewall, of the receiving groove, has an outwardtaper at an angle of at least 60° relative to a plane perpendicular tothe central axis.135. A main filter cartridge according to any one of characterizations125-134 wherein: (a) the housing seal arrangement comprises a radiallyinwardly directed housing seal member.136. A main filter cartridge according to characterization 131 wherein:(a) the housing seal member is positioned at a location surrounded bythe media.137. A main air filter cartridge according to any one ofcharacterizations 125-136 wherein: (a) the media tapers downwardly inextension from the first end of the second end.138. A main air filter cartridge according to any one ofcharacterizations 125-137 wherein: (a) the media is pleated.139. A main filter cartridge according to any one of characterizations125-138 wherein: (a) the ring tip projects to a location at least 5%from the media second end toward the media first end.140. A main filter cartridge according to any one of characterizations125-138 wherein: (a) ring tip projects to a location at least 10% fromthe media second end toward the media first end.141. A main filter cartridge according to any one of characterizations125-140 wherein: (a) ring tip projects to a location at least 20% fromthe media second end toward the media first end.142. A method of installing a main air filter cartridge according to anyone of characterizations 125-141 in a housing of an air cleanerassembly; the method comprising a step of: (a) pushing the main airfilter cartridge over a support having a resilient cushion memberthereon until: (i) the housing seal arrangement is in releasable sealingengagement with the air cleaner housing; and, (ii) the resilient cushionmember is in releasable supporting engagement with the inner surface ofthe central recess defined by the central projection on the centralclosure member.143. A method according to characterization 142 wherein: (a) theresilient cushion member is positioned on a safety cartridge in accordwith any one of characterizations 1-84.144. A method according to any one of characterizations 142 and 143wherein: (a) the air cleaner assembly is a filter assembly in accordwith any one of characterizations 85-122.

The principles, techniques, and features described herein can be appliedin a variety of systems, and there is no requirement that all of theadvantageous features identified be incorporated in an assembly, systemor component to obtain some benefit according to the present disclosure.In addition, the dimensions characterizing an example system are meantto indicate a usable construction, and variations from them arepossible.

1-17. (canceled)
 18. A filter cartridge comprising: (a) an extension ofmedia surrounding an open interior and having a first end and a secondend; (i) at the first end, the media having no pleat greater than 3 mmin depth; and, (ii) at the second end, the media comprising a pluralityof pleats each having a pleat depth of at least 10 mm.
 19. A filtercartridge according to claim 18 wherein: (a) the extension of mediasurrounds a central axis; (i) the media being pleated adjacent thesecond end and defining a plurality of inner pleat tips extending at anacute angle, relative to a plane perpendicular to a central axis, of nogreater than 89°, in extension toward the first end; and, (ii) the mediabeing non-pleated at the first end.
 20. A filter cartridge according toclaim 18 including: (a) a radially directed housing seal memberpositioned at a location within 50 mm of the first end of the extensionof media; (i) the filter cartridge having a maximum, undistorted, radialwidth dimension, at a location in radial overlap with the media and thehousing radial seal member, of at least 10 mm less than a maximum pleatdepth of the extension of media adjacent the second end of the extensionof media.
 21. A filter cartridge according to claim 18 including: (a) amedia support; (i) the media including a non-pleated, free, tip sectionadjacent the media first end that extends, axially, in a direction awayfrom the second end, an axial distance of at least 0.5 mm beyond anearest adjacent portion of the media support.
 22. A filter cartridgeaccording to claim 18 including: (a) a housing radial seal memberpositioned at a location within 40 mm of the first end.
 23. A filtercartridge according to claim 18 wherein: (a) the media surrounds anddefines a central cartridge axis; and, (b) the media includes aplurality of inner pleats having inner pleat tips extending at an acuteangle of no more than 88°, relative to a plane perpendicular to acentral axis, in extension toward the first end.
 24. A filter cartridgeaccording to claim 18 wherein: (a) the media surrounds and defines acentral cartridge axis; and, (b) the media includes a plurality of innerpleats having inner pleat tips extending at an acute angle within therange of 70°-88°, inclusive, relative to a plane perpendicular to thecentral axis, in extension toward the first end.
 25. A filter cartridgeaccording to claim 18 wherein: (a) the media surrounds and defines acentral cartridge axis; and, (b) the media includes a plurality of outerpleats and a plurality of inner pleats; (i) the inner pleats including aplurality of inner pleat tips extending at a first angle relative to aplane perpendicular to the central axis, in extension from the secondend toward the first end; and, (ii) the outer pleats including aplurality of outer pleats tips extending at a second angle, relative toa plane perpendicular to the central axis, in extension from the secondend toward the first end; (ii) the second angle being greater than thefirst angle, with respect to a plane perpendicular to the central axis.26. A filter cartridge according to claim 18 wherein: (a) the mediasurrounds and defines a central cartridge axis; and, (b) the mediaincludes a plurality of outer pleats having outer pleat tips extendingat an angle within the range of 88°-90°, inclusive, relative to a planeperpendicular to the central axis, in extension from the second endtoward the first end.
 27. A filter cartridge comprising: (a) anextension of media surrounding a central axis and defining an openinterior; (i) the media having first and second ends; and, (ii) themedia being pleated adjacent the second end and defining a plurality ofinner pleat tips extending at an acute angle, relative to a planeperpendicular to a central axis, of no greater than 89°, in extensiontoward the first end; and, (iii) the media being non-pleated at thefirst end.
 28. A filter cartridge comprising: (a) an extension of mediasurrounding an open interior and having a first end and a second end;(i) the media comprising a plurality of pleats each having a pleat depthdecreasing in extension from the second end in a direction toward thefirst end; and, (b) a housing radial seal member positioned at alocation within 50 mm of the first end.
 29. A filter cartridgecomprising: (a) an extension of media having a first end and a secondend; (i) the media surrounding and defining an open interior; (ii)adjacent the second end, the extension of media being pleated; and, (b)a radially directed housing seal member positioned at a location within50 mm of the first end of the extension of media; (i) the filtercartridge having a maximum, undistorted, radial width dimension, at alocation in radial overlap with the media and the housing radial sealmember, of at least 10 mm less than a maximum pleat depth of theextension of media adjacent the second end of the extension of media.30. A filter cartridge comprising: (a) an extension of media surroundingan open interior and having a first end and a second end; (i) the media,adjacent the second end, being pleated and comprising a plurality ofoutwardly directed pleats and a plurality of inwardly directed pleats;and, (ii) each one of the plurality of outwardly directed pleats havinga pleat tip with an outer perimeter tip shape, (iii) an inner perimetertip shape, of each pleat tip of the plurality of inwardly directedpleats, being narrower than the pleat tip shape of each one of theplurality of outwardly directed pleats; (A) the outer pleat tips havingan outer, perimeter, pleat shape at a location adjacent the second endwith a radius of at least 4 mm.
 31. A filter cartridge according toclaim 31 including: (a) a radially directed housing seal member at alocation within 40 mm of the first end of the media.
 32. A filtercartridge according to claim 31 including: (a) a radially directedhousing seal member positioned within 30 mm of the first end of themedia.
 33. A filter cartridge according to claim 31 including: (a) aradially directed housing seal member positioned at a location within 20mm of the first end of the media.
 34. A filter cartridge according toclaim 31 including: (a) a radially directed housing seal memberpositioned at a location within 15 mm of the first end of the media. 35.A filter cartridge according to claim 31 including: (a) a radiallyoutwardly directed housing seal member.
 36. A filter cartridgecomprising: (a) an extension of media surrounding an open interior andhaving a first end and a second end; (i) the extension of media beingpleated adjacent the second end; and, (b) a media support; (i) the mediaincluding a non-pleated, free, tip section adjacent the media first endthat extends, axially, in a direction away from the second end, an axialdistance of at least 0.5 mm beyond a nearest adjacent portion of themedia support.